FRAG详解
fragroute安装及使用
FragrouteFragroute的原理就不说了,网上大部分都是关于fragroute的文章。
大体就是Fragroute 欺骗NIDS检测的方法是在保证victim的ip stack可以正确重组的情况下,对含有攻击特征串报文进行tcp分段和ip分片,同时塞入大量的错误分片报文,打乱顺序后发出,从而达到欺骗NIDS的目的。
安装:网上的一些安装方法还是不好使,因为还要装linux下的一些其他软件,比如gcc,c、c++编译器,flex等。
我用的的redhat 企业版5的linux系统,将安装总结一下。
首先需要将gcc装上,装gcc之前需将glibc-devel和libgomp装上,装该两个软件之前还要一些提示说需装上其他软件才行,按照提示都装上(大概4-5个)。
装好后,如果就开始安装libpcap-0.9.5软件(fragroute的一个组件)的话,系统会提示这就需要安装flex了,安装好flex后,如果再安装libpcap-0.9.5软件的话,则会显示如下错误这是因为没有安装byacc,安装好后就可安装fragroute了。
(也可以提示错误,可能还有什么要装的,装上就行了)。
按如下步骤安装fragroute在Linux系统安装,fragroute需要三个库:libpcap、libdnet和libevent。
下载了fragroute 和需要的库之后,执行以下命令就可以把fragroute安装到系统中:#tar zxvf libpcap-x.x.tar.gz#cd libpcap-x.x#./configure &&make &&make install#cd ..#tar zxvf libdnet-x.x.tar.gz#cd libdnet-x.x#./configure&&make&&make install#cd ..#tar zxvf libevent-x.x.tar.gz#cd libevent#./configure&&make&&make install#cp /usr/local/lib/libevent-1.2.so.1 /usr/lib/#cd ..#tar zxvf fragroute-x.x.tar.gz#cd fragroute-x.x#./configure&&make&&make install这些步骤完成之后,基本上完成了fragroute的安装。
fragement详解
fragement详解Fragment(片段)是编程中的一个概念,指的是在Android开发中可以独立存在的模块化组件。
相较于Activity(活动),Fragment有更好的灵活性、可重用性和扩展性。
本文将详细解释Fragment的定义、使用方法、生命周期、与Activity的关系等内容,以帮助读者深入了解Fragment的优点和实践。
第一部分:Fragment定义和使用方法一、Fragment定义Fragment是Android提供的一种用户界面组件,可以嵌入到Activity中进行布局和交互。
每个Fragment都有自己的生命周期,可以独立接收用户输入、响应事件、更新UI等。
Fragment可以看作是一种轻量级的Activity,但与Activity不同的是,Fragment必须依附于一个Activity才能使用。
二、Fragment使用方法要在项目中使用Fragment,首先需要确保你的项目使用了适当的版本和依赖库。
在Android Studio中,可以在build.gradle 文件中添加以下代码来引入Fragment支持:```implementation 'androidx.fragment:fragment:1.3.0'```然后,在XML布局文件中定义Fragment的容器。
在Activity 中可以添加一个`<FrameLayout>`元素作为容器,如下所示:```<FrameLayoutandroid:id="@+id/fragment_container"android:layout_width="match_parent"android:layout_height="match_parent" />```接着,在Activity中实例化一个Fragment对象,并将其添加到容器中。
大数据的传输过程详解
数据传输过程详解一、FTP 客户端发送数据到FTP 服务器端,详述其工作过程。
两台机器的连接情况如下图所示:详细解答如下 1.1、假设初始设置如下所示: 客户端FTP 端口号为:32768 服务器端FTP 端口号为:21设备设置PC1(客户端):MAC 地址(MAC1):A01 IP 地址(IP1):192.168.1.1 子网掩码:255.255.255.0 默认网关:192.168.1.2 PC2(服务器端):MAC 地址(MAC2):A02 IP 地址(IP2):192.168.2.1 子网掩码:255.255.255.0 默认网关:192.168.2.2Switch1:MAC 地址列表端口 MAC 地址 1 A01 2 A03 Switch2:MAC 地址列表 端口 MAC 地址 1 A02 2 A04 Router :端口S0设置 MAC 地址(MAC3):A03 IP 地址(IP1):192.168.1.2 端口S1设置MAC 地址(MAC4):A04 IP 地址(IP1):192.168.2.2路由表网络号端口号 192.168.1.0 S0 192.168.2.0 S11.2、不同网络段上的两台计算机通过TCP/IP 协议通讯的过程如下所示: 协议是水平的,服务是垂直的。
物理层,指的是电信号的传递方式,透明的传输比特流。
链路层,在两个相邻结点间的路线上无差错地传送以帧为单位的数据。
网络层,负责为分组交换网上的不同主机提供通信,数据传送的单位是分组或者包。
传输层,负责主机中两个进程之间的通信,数据传输的单位是报文段。
网络层负责点到点(point-to-point )的传输(这里的“点”指主机或者路由器),而传输层负责端到端(end-to-end )的传输(这里的“端”指源主机和目的主机)。
1.3、数据包的封装过程),在网络层叫做数据不同的协议层对数据包有不同的称谓,在传输层叫做段(segment)。
Android开发教程之Frag...
Android开发教程之Frag...本⽂实例讲述了Android开发教程之Fragment定义、创建与使⽤⽅法。
分享给⼤家供⼤家参考,具体如下:概述Fragment是activity的界⾯中的⼀部分或⼀种⾏为。
你可以把多个Fragment们组合到⼀个activity中来创建⼀个多⾯界⾯并且你可以在多个activity中重⽤⼀个Fragment。
你可以把Fragment认为模块化的⼀段activity,它具有⾃⼰的⽣命周期,接收它⾃⼰的事件,并可以在activity运⾏时被添加或删除。
Fragment不能独⽴存在,它必须嵌⼊到activity中,⽽且Fragment的⽣命周期直接受所在的activity的影响。
例如:当activity暂停时,它拥有的所有的Fragment们都暂停了,当activity销毁时,它拥有的所有Fragment们都被销毁。
然⽽,当activity运⾏时(在onResume()之后,onPause()之前),你可以单独地操作每个Fragment,⽐如添加或删除它们。
当你在执⾏上述针对Fragment的事务时,你可以将事务添加到⼀个棧中,这个栈被activity管理,栈中的每⼀条都是⼀个Fragment的⼀次事务。
有了这个栈,就可以反向执⾏Fragment的事务,这样就可以在Fragment级⽀持“返回”键(向后导航)。
当向activity中添加⼀个Fragment时,它须置于ViewGroup控件中,并且需定义Fragment⾃⼰的界⾯。
你可以在layoutxml⽂件中声明Fragment,元素为:<fragment>;也可以在代码中创建Fragment,然后把它加⼊到ViewGroup控件中。
然⽽,Fragment不⼀定⾮要放在activity的界⾯中,它可以隐藏在后台为actvitiy⼯作。
接下来讲如何使⽤fragment,包括fragment在加⼊activity的后退棧中时如何保持⾃⼰的状态,如何与activity以及其它fragment 们共享事件,如何显⽰在activity的动作栏,等等。
(新)黑屏电子商务系统指令详解
黑屏电子商务系统指令详解查看AV屏政策信息: QCPS (需先执行AV指令查询航班)查看某一航班号政策信息: QCPS 航班号/日期(日期格式08JAN) 代理人借记卡支付: ADPAY (需先执行RT指令提取编码)代理人赊销支付: ASPAY (需先执行RT指令提取编码)代理人用户退款(含逆分账): REFD 订单号显示支付列表: QMOL/日期(日期格式08JAN)显示退款列表: QREFD/日期(日期格式08JAN)Eterm指令、航信订票出票指令、黑屏订票指令查询1. 航班座位可利用显示>A V: H/城市对/日期/时间/ 航空公司代码(或GDS代码)2. 最早有座位航班查询>FV: 城市对/日期/起飞时间/座位数/航空公司代码(或GDS代码)/经停标志/ 舱位3. 航班飞行周期的查询>SK: 城市对/日期/时间/航空公司代码/ 舱位4. 航班经停点和起降时间的显示指令>FF: 航班号/日期5. 指定日期的航段上的航班详细信息显示>DSG:C/航班号/座位等级/日期/航段或RT之后,>DSG: 航班序号..............................................................................................信息查询及辅助功能一、24小时北京天气预报WF >WF 城市三字代码二、机场转机信息查询DSM >DSM: PEK三、机场、国家、航空公司代码查询CNTD/CD1)查询城市三字代码>CNTD T/BEIJING2)查询城市名称>CD PEK3)查询一个国家所有城市>CNTD A/CN4)查询国家全称>CNTD C/CN5)查询国家两字码>CNTD N/CHINA6)查询航空公司信息>CNTD D/CA7)查询航空公司两字代码>CNTD M/AIR CHINA四、计算CO1)四则运算>CO 100+22)计算北京和巴黎的时差>CO T/PEKCDG3)显示巴黎10月1日0点的GMT标准时间>CO T/CDG/1OCT/00004)英里换算成公里>CO K/英里数5)公里换算成英里>CO M/公里数五、日期查询DATE1)显示当前日期和星期几>DATE2)显示10天,90天后的日期>DATE 10/903)显示2004年1月1日的前2天,及后20天的日期>DA TE 1JAN04/-2/20六、时间查询TIME1)显示当前时间>TIME2)北京时间2004年1月1日零点的巴黎时间>TIME 1JAN04/0000/CDG 生活论坛m8tEdg553A3)纽约时间2004年1月1日零点的北京、巴黎时间>TIME NYC/1JAN/0000/PEK/CDG七、长度、重量、温度换算CV1)100公里换算成英里>CV 100KM2)100英里换算成公里>CV 100MI3)摄氏35度转化为华氏度>CV 35C4)华氏95度转化为摄氏度>CV 95F5)10英镑转化为公斤>CV 10LB6)10公斤转化为英镑-磅>CV 10KG八、查询中文信息YI1)显示所有静态信息的目录>YI2)显示不含副标题的公告>YI标题3)显示有副标题的公告>YI I/某标题九、旅游信息查询TIM1)查询签证信息>TIM TIFV2)查询健康检疫信息>TIM TIFH3)同时查询签证、健康检疫信息>TIM TIFA4)查询与出入境有关的信息>TIM TIDFT/城市/章节/小标题/页码5)显示TIM帮助功能>TIM TIHELP6)显示TIM中有关规则>TIM TIRULES7)显示综合旅游信息新闻>TIM TINEWS8)显示下一页>TIPN9)显示上一页>TIPB..............................................................................................建立PNR一、航段预订1)直接建立航段组SS>SS CA1537/Y/1OCT/PEKNKGNN1/1225 14002)间接建立航段组SD>A V PEKCAN>SD 1Y13)OPEN航段的建立SN>SN YY/F/PEKCAN>SN CZ/F/PEKCAN4)ARNK段的建立SA >SA TSNPEK5) 旅客行程提示>SA MU5119Y1OCT SHAPEK HK6)调整航段顺序CS>CS 2/1二、姓名输入NM1)英文姓名的输入>NM 1STEPHEN/HAETTI 1ZHU/QI2)同姓旅客英文名的输入>NM 2ZHANG/JIAN/QIANG3)中文姓名的输入>NM 1杨振振1马永4)无人陪伴儿童姓名输入>NM 1马晓涌(UM4)5)带一个婴儿的******输入姓名>NM 1马永>XN IN/马晓涌INF(MAR01)P16)建立一个团名为CHANGYOU的12人的团体PNR>GN 12CHANGYOU三、联系方式CT >CT PEK/1234567四、证件信息输入SSR (注意:CA表示相应的航空公司代码)1) 国内旅客>SSR FOID CA HK/证件代码及号码/Pn 证件种类代码:NI-身份证;PP-护照;ID-其他证件2) 国际旅客>SSR PSPT CA HK/护照号码/国籍/旅客生日/旅客姓/旅客名/性别及婴儿标识/持有人标识/Pn注:下划线部分为必输项五、出票时限TKTL>TK TL/1200/01OCT/BJS123六、手工票号输入TKT>TKT/783-2203752149/P1七、票价信息的简易输入FC/FN 八、选择制定航段进行票价计算或打票SEL>SEL: 指定航段序号九、国内BSP客票自动生成FN/FC/FP项:>PA T:十、国际客票经过QTE/XS FSQ, 自动生成FN/FC项:>DFSQ:十一、付款方式组FP>FP:CASH/ CHECK,CNY十二、签注信息组EI 十三、旅游代码组TC (一般按照航空公司要求输入) 十四、打票预览TKTV>TKTV: 打票机序号十五、票号自动传输STN>STN: 票号/Pn/指定航段序号十六、客票打印DZ打印PNR中所有人的客票>DZ:1仅打印第一个******所携带的婴儿客票>DZ:1/P1, INF仅打印第一个******的客票>DZ:1/P1, ADL打印PNR中所有婴儿客票>DZ:1,INF打印PNR中所有******客票>DZ:1, ADL特殊服务SSR一、查看航班座位图ADM>ADM:航段序号/航段二、进行机上座位预订ASR>ASR: 航段序号/座位号三、里程输入>SSR FQTV承运航空公司代码HK1/发卡航空公司代码卡号/Pn四、其他特殊服务的申请>SSR 特殊服务代码航空公司NN数量/Pn/Sn常用特殊服务代码:机位申请NSSA:无烟靠走廊的座位NSSW:无烟靠窗的座位NSST:无烟座位SMSA:吸烟靠走廊的座位SMSW:吸烟靠窗的座位SMST:吸烟座位特殊餐食A VML:亚洲素食BLML:流食CHML:儿童餐DBML:糖尿病患者餐FPML:水果拼盘SFML:海洋餐HFML:高纤维餐HNML:印度餐BBML:婴儿餐KSML:犹太教餐LCML:低卡路里餐LFML:低胆固醇、低脂肪餐LSML:无盐餐MOML:穆斯林餐VLML:素食(含糖、鸡蛋) VGML:素食(无糖)其他PETC:宠物(需要详细说明) BSCT:摇篮车/吊床/婴儿摇篮BIKE:自行车(须说明数量) SLPR:机舱内床铺(不包括担架) BLND:盲人旅客(如果有导盲犬或其他动物陪伴,须详细说明) BULK:超大行李(须说明数量、重量和尺寸)CBBG:放置机舱行李(购买了额外座位,须说明数量,重量及尺寸)DEAF:聋哑旅客(如果有助听狗或其他动物陪伴,须详细说明)DEPA:被驱逐出境(有人陪伴) DEPU:被驱逐处境(无人陪伴)XBAG:额外行李(须说明数量、重量和尺寸)FRAG:易碎行李(须说明数量、重量和尺寸)MEDA:健康状况(需要旅客医疗状况证明)SPEQ:体育设施(须指明设备类型、数量、重量和尺寸)STCR:担架旅客UMNR:无人陪伴儿童PNR提取和修改一、PNR提取1)记录编号提取PNR >RT 记录编号2)根据旅客名单提取PNR >RT旅客姓名/航班号/日期3)提取完整PNR >RT C/记录编号4)提取PNR的历史部分>RT U5)返回到PNR的现行部分>RT A6)按照航班的旅客名单提取>ML C/CA1301/10DEC >RT 序号7) 提取本部门在该航班的所有订座记录(RR、HK、HN、HL、HX)>ML C/CA1321/7OCT8)提取所有团体PNR记录>ML G/CA1321/7OCT9)提取所有订妥座位的记录>ML B/CA1321/7OCT10)提取所有未证实座位的记录>ML U/CA1321/7OCT11)提取所有非团体PNR记录>ML NG/CA1321/7OCT二、国内航空公司记录的提取和转换>RRT: V/航空公司记录编号/航班号/日期>@OK三、记录分离SP >SP 1/3四、记录修改1)旅客姓名修改>1/1杨振2)删除姓名组以外的内容>XE 序号3)取消PNR>XEPNR@五、记录封口@1)正常封口>@2)以下几种情况可使用@K封口>@Ka)将KK,KL或TK变为HKb)将UU,US或TL变为HLc)将TN变为HNd)将带有NI,UC,UN的项移到PNR的历史部分3)以下情况可使用@I封口>@Ia)航段不连续b)有航班变更标识c)两个连接航段的停留时间小于最小连接时间公布运价的查询一、国内公布运价查询:1).查询城市对间当前可用票价FD>FD:城市对/日期/航空公司代码/查询选项(S排序由低到高;L最低价) 2).运价限制条件信息查询PFN>PFN: 规则号/ 承运人或在FD的基础上>PFN: 运价序号3).查询运价的航线限制PFR在FD基础上有航线限制标识的情况下>PFR: 运价序号二、航空公司净价查询:(需要航空公司授权)1.查询运价总则>NFN:GR00/CA2.按城市对查询票价信息:>NFD:PEKLON/CA3.指定旅行日期查询:>NFD:PEKLON/21MAY04/CA4.查询单程票价>NFD:PEKLON/CA*OW5.查询M舱票价>NFD:PEKLON/CA#M6.查询运价基础为HIT的票价>NFD:PEKLON/CA@HIT7.查询学生票价>NFD:PEKLON/CA*SD8.查询团队票价>NFD:PEKLON/CA*GC9.显示第3条票价的规则限制>NFN:310.显示第3条票价的航线规定>NFR:311.显示第4条票价的签注信息>NFE:412. 修改查询条件,快速重新查询票价:>NFC:13.指定航线查询>NFQ:PEK15MAY04LONPEK/CA14. 按协议查询>NFL:/CA15. 显示第2条协议的内容>NFL:216.显示第2条协议中的所有票价>NFL:2*ALL操作流程示例:某北京旅客要在5月1日去新加坡或吉隆坡,5月7日回北京,希望获得最便宜的往返客票。
fraggle攻击原理
fraggle攻击原理Fraggles攻击原理背景介绍•什么是Fraggles攻击?•Fraggle攻击为何具有资深创作者的关注?概述•Fraggle攻击是一种网络攻击手法,旨在消耗目标网络的带宽、资源和服务可用性。
•攻击者通过大量伪造的目标IP地址,向目标网络发送特制的UDP 数据包。
•这些数据包利用了IP协议中的一个特性,即IP头部信息可伪造,使得攻击流量无法追溯到源头。
•Fraggles攻击以快速、高强度的方式向目标网络发送UDP包,造成网络拥塞并可能导致网络服务中断。
攻击原理详解1.伪造IP地址–攻击者使用伪造的源IP地址来发送网络数据包,使得追溯攻击源变得困难。
–这些伪造的IP地址通常是被攻击目标网络内的合法IP地址,使得目标更难以区分攻击流量和合法流量。
–攻击者可以使用特殊工具或技术,如IP Spoofing,来实现IP地址伪造。
2.利用UDP协议–Fraggle攻击利用UDP协议进行攻击,主要原因是UDP协议的缺乏连接性和验证性。
–UDP没有建立连接的握手过程,也没有丢包重传机制,因此攻击者可快速发送大量的UDP数据包,提高攻击效果。
–此外,UDP协议也无法验证数据包的完整性和真实性,使得攻击者可以更容易进行IP地址伪造。
3.攻击流程–攻击者首先扫描目标网络,获取合法的目标IP地址。
–攻击者使用伪造的IP地址,利用多个主机发送大量的UDP 数据包到目标网络。
–这些UDP数据包通常使用一些协议或服务的特定端口,如DNS、NTP、Chargen等,进一步增加攻击效果。
–攻击目标网络的服务器接收到这些UDP包后,会尝试回复伪造的源IP地址,从而进一步加重了网络负载和资源消耗。
防御措施1.路由器配置–确保路由器配置正确,对传入网络流量进行筛选和限制。
–禁止传入的UDP数据包使用源IP地址与目标IP地址相同,以阻止IP地址伪造。
2.防火墙设置–配置防火墙规则,限制某些协议或端口的传入流量。
–配置反向路径过滤(Reverse Path Filtering)等,以减少IP地址伪造攻击的可能性。
linux嗅探工具Dsniff详解
linux嗅探工具Dsniff详解Dsniff是一个著名的网络嗅探工具包。
其开发者Dug Song早在1999年12月,以密歇根大学CITI研究室(Center for Information Technology Integration)的研究成果为基础,开发了这个后来具有很大影响力的网络安全工具包。
Dug Song开发Dsniff的本意是揭示网络通信的不安全性,借助这个工具包,网络管理员可以对自己的网络进行审计,也包括渗透测试。
但万事总有其两面性,Dsniff所带来的负面作用也是“巨大”的,首先它是可以自由获取的,任何拥有这个工具包的人都可能做“非正当”的事,其次,Dsniff里面的某些工具,充分揭示了一些安全协议的“不安全性”,例如针对SSH1和SSL的MITM(Man-In-The-Middle)攻击工具—SSHmitm和Webmitm。
SSH1和SSL都是建立网络通信加密通道的机制,向来被认为是很安全的,但人们在具体使用时,往往因为方便性上的考虑而忽视了某些环节,造成实事上的不安全。
所以说,最大的不安全性,往往并不在于对安全的一无所知,而在于过于相信自己的安全。
Dub Song在2000年12月发布了Dsniff的v2.3版本,该版本支持OpenBSD、Linux、Solaris 系统平台。
目前,最新版本是2001年3月发布的v2.4b1的Beta版。
Dsniff的下载网址:/~dugsong/dsniff/除了针对Unix系统的版本,从网上也可以得到Windows平台上运行的Dsniff早期版dsniff工具介绍纯粹被动地进行网络活动监视的工具,包括:dsniff、filesnarf、mailsnarf、msgsnarf、urlsnarf、webspy针对SSH和SSL的MITM(Man-In-The-Middle)“攻击”工具,包括sshmitm和webmitm 发起主动欺骗的工具,包括:arpspoof、dnsspoof、macof其它工具,包括tcpkill、tcpnicedsniffdsniff是一个密码侦测工具,他能够自动分析端口上收到的某些协议的数据包,并获取相应的密码。
2023年高考英语阅读理解 专题04 猜词题
2023年高考英语阅读理解专题04 猜词题专题04 猜词题Part1 技巧导图Part2 知识详解Part3 词义猜测题特点Part4 词义猜测题七大猜词技巧Part5 构词法基础知识Part1 技巧导图Part2 知识详解Part3 词义猜测题特点猜词悟义是应用英语的重要能力,也是高考阅读理解中必考的题型。
它不但需要准确无误地理解上下文,而且要有较大的泛读量,掌握或认识较多的课外词汇。
同时,考生应掌握一些猜词技巧,通过定义、同位、对比、因果、常识、同义、反义、构词、常识及上下文线索等确定词义。
词义猜测题思维导图【设问形式】•The underlined word “ … ” refers to/ (probably) means .•“…” as used in the passage can best be defined as…•What do you think the expression “…” stands for?•What does the underlined word “…” refer to in the last paragraph?•Which of the following words can take the place of the word “ … ”?•The underlined word “…” could best be replaced by…•Which of the following has the closest meaning to the word “ … ”?•What does the author mean by “…” in paragraph 2?Part4 词义猜测题七大猜词技巧1.根据定义或上下文解释进行猜测有时短文中出现一个需要猜测其意义的词或短语,下面接着出现其定义或解释。
标点符号,如逗号后的解释(名词同位语)、破折号后的解释、括号内的解释等。
其它语言学习-德语学习表示质疑、疑问的常用句型
德语学习表示质疑、疑问的常用句型德语学习表示质疑、疑问的常用句型德语中表示疑问的句型一般由名词Frage、动词fragen和形容词fraglich构成。
由于Frage 是个“问题”,所以后面的从句都是以疑问代词和疑问副词ob、warum、wenn、wann、wie、wo等开头,绝对不能接dass从句。
常用的句型如下:1. Die Frage ist/lautet, wie/ob/wann... 问题是...Jetzt lautet die Frage, ob die Juden in Europa überhaupt eine Zukunft haben. (FAZ 20150729)(品德德语培训)现在的问题就是,犹太人究竟在欧洲究竟有没有未来。
2. Es stellt/erhebt sich die Frage, ob/wo...提出的问题是...Frage作主语时一般用反身动词sich stellen或sich erheben作谓语动词,后者出现频率比较少。
这个组合其实也比较好理解,因为Frage作宾语时所支配的动词就是stellen,即eine Frage an jn. stellen(向某人提出一个问题),当Frage作主语时,自然要和其反身动词sich stellen搭配。
如果句首还有其它成分,则代词es 省略。
Mit der Versch?rfung der Griechenland-Krise stellt sich die Frage, wie die Verluste der einzelnen L?nder im Falle eines griechischen Staatsbankrotts und eines Konkurses der griechischen Gesch?ftsbanken einzusch?tzen w?ren. (FAZ 20150629)随着希腊危机的愈演愈烈就提出了这样一个问题:在希腊国家破产和希腊商业银行倒闭的情况下如何估算各个国家的损失。
考研英语(一)高频重点单词详解—2009年Text 2(上)
考研英语(一)高频重点单词详解—2009年Text 2(上)这篇文章是一篇历史类话题的文章,讨论美国的开国元勋们所不为人知的一面---对于奴隶制度的暧昧态度。
他们深知奴隶制的危害,却因文化和政治的原因继续支持奴隶制度的存在。
通过这篇文章我们可以更全面地了解到美国历史。
以下是本文中出现的10个高频重点单词,就让我们一起来学习吧!1.2 transplant [træns'plɑːnt]v. 移植;转移【词根记忆】:trans(=from…to 从…到)+ plant(种植)→移植【短语搭配】:organ transplant 器官移植【真题例句】:So he hired a dentist to transplant nine teeth into his jaw--having extracted them from the mouths of his slaves.于是,华盛顿雇牙医往他的口腔内移植了九颗牙齿--- 这些牙齿是从他的奴隶的口中拔出的。
2. 4 extract [ˈekstrækt]v. 提炼,提取;摘取,摘录;拔牙【词根记忆】:ex(=out外,出)+ tract(拉,抽)→抽取,提取【真题例句】:You have all heard it repeated that men of science work by means of induction and deduction, that by the help of these operations, they, in a sort of sense, manage to extract from Nature certain natural laws, and that out of these, by some special skill of their own, they build up their theories. 你们都多次听说过,科学家是利用归纳法和演绎法工作,从某种意义上来说,他们用这种方法力图找到某些自然规律,然后他们根据这些规律和自己的某种特有的技能建立他们自己的理论。
hping使用参数详解
-l --tcpck 设置TCP ack的
-Q --seqnum 搜集序列号的,这对于分析TCP序列号有很大作用,例如:
#hping2 win98 --seqnum -p 139 -S -i u1 -I eth0
HPING uaz (eth0 192.168.4.41): S set, 40 headers + 0 data bytes
ICMP选项
-C --ICMPTYPE TYPE 指定ICMP类型,缺省是ICMP ECHO REQUEST
-K --ICMPCODE CODE 指定ICMP代号,缺省0
--icmp-ipver 把IP版本也插入IP头,
--icmp-iphlen 设置IP头的长度,缺省为5 (32字节)
-m --mtu mtu value 用此项后 ID数值变得很大 50000没指定此项时3000-20000左右
-o --tos hex tos TOS=TYPE OF SERVICE
-G --rroute 记录路由,可以看到详悉的数据等等,最多可以经过9个路由,即使主机屏蔽了ICMP报文,路由只涉及IP,所以任可以记录,在TCP UDP下,也可以记录路由的
HPING参数,可以用HPING -H来看
-H --HELP 显示帮助
-v -VERSION 版本信息
-c --count count 发送数据包的次数 关于countreached_timeout 可以在hping2.h里编辑
-i --interval 包发送间隔时间(单位是毫秒) 缺省时间是1秒,此功能在增加传输率上很重要,在idle/spoofing扫描时此功能也会被用到,可以参考hping-howto获得更多信息
AndroidX下使用Activity和Fragment的变化详解
AndroidX下使⽤Activity和Fragment的变化详解过去的⼀段时间,AndroidX 软件包下的 Activity/Fragmet 的 API 发⽣了很多变化。
让我们看看它们是如何提升Android 的开发效率以及如何适应当下流⾏的编程规则和模式。
本⽂中描述的所有功能现在都可以在稳定的 AndroidX 软件包中使⽤,它们在去年均已发布或移⾄稳定版本。
在构造器中传⼊布局 ID从 AndroidX AppCompat 1.1.0 和 Fragment 1.1.0 ( 译者注:AppCompat 包含 Fragment,且 Fragment 包含 Activity,详情见【整理】Jetpack 主要组件的依赖及传递关系 )开始,您可以使⽤将 layoutId 作为参数的构造函数:class MyActivity : AppCompatActivity(yout.my_activity)class MyFragmentActivity: FragmentActivity(yout.my_fragment_activity)class MyFragment : Fragment(yout.my_fragment)这种⽅法可以减少 Activity/Fragment 中⽅法重写的数量,并使类更具可读性。
⽆需在Activity 中重写 onCreate() 即可调⽤setContentView() ⽅法。
另外,⽆需⼿动在Fragment中重写 onCreateView 即可⼿动调⽤ Inflater 来扩展视图。
扩展 Activity/Fragment 的灵活性借助 AndroidX 新的 API ,可以减少在 Activity/Fragment 处理某些功能的情况。
通常,您可以获取提供某些功能的对象并向其注册您的处理逻辑,⽽不是重写 Activity / Fragment 中的⽅法。
这样,您现在可以在屏幕上组成⼏个独⽴的类,获得更⾼的灵活性,复⽤代码,并且通常在不引⼊⾃⼰的抽象的情况下,对代码结构具有更多控制。
常见IP碎片攻击详解
常见IP碎片攻击详解创建时间:2002-01-12引用时间:2009-02-03文章属性:引用文章来源:引用来源:/articles/200201/326.html文章原作者:Sinbad (microbin_at_)文档整理:big-time本文简单介绍了IP分片原理,并结合Snort抓包结果详细分析常见IP碎片攻击的原理和特征,最后对阻止IP碎片攻击给出一些建议。
希望对加深理解IP协议和一些DoS攻击手段有所帮助。
1. 为什么存在IP碎片-=-=-=-=-=-=-=-=-=-=-=链路层具有最大传输单元MTU这个特性,它限制了数据帧的最大长度,不同的网络类型都有一个上限值。
以太网的MTU是1500,你可以用 netstat -i 命令查看这个值。
如果IP层有数据包要传,而且数据包的长度超过了MTU,那么IP层就要对数据包进行分片(fragmentation)操作,使每一片的长度都小于或等于MTU。
我们假设要传输一个UDP数据包,以太网的MTU为1500字节,一般IP首部为20字节,UDP首部为8字节,数据的净荷(payload)部分预留是1500-20-8=1472字节。
如果数据部分大于1472字节,就会出现分片现象。
IP首部包含了分片和重组所需的信息:+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Identification |R|DF|MF| Fragment Offset |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+|<-------------16-------------->|<--3-->|<---------13---------->|Identification:发送端发送的IP数据包标识字段都是一个唯一值,该值在分片时被复制到每个片中。
德语俚语汉德对照详解(4)
31.den gro?en Onkel laufen([⼝]脚尖向⾥颠着⾛) über die gro?e Zehe, einw?rts laufen. - Aus dem franz?sischen"le grand ongle" ("ongle" = Nagel, Klaue, Kralle, Huf). 出⾃法⽂中的"le grand ongle" ,其中"ongle"意为脚。
32.Penne ([⼝,学⽣⽤语]学校,⽂科中学)= Schule: Aus dem lateinischen pennale = Federkasten, -etui, entstanden. 相当于“Schule”,出⾃意⼤利⽂的“pennale”(原意为⽂具盒) 33.Schmiere stehen(为某⼈在进⾏⾮法活动或恶作剧时把风,望风) Bei Diebstahl oder anderen Vergehen aufpassen, da? die T?ter nicht überrascht werden. - Aus der Gaunersprache, dem hebr?ischen schemirah = Bewachung, Beaufsichtigung entlehnt. 在偷窃或进⾏其他犯罪活动时,为主犯把风。
出⾃希伯来⽂中的⿊话“schemirah”,意为看顾,照看。
34.Sich verfranzen([⼝]迷路) Sich verirren. - Fliegersprache. "Franz" wurde im ersten Weltkrieg der Beobachter eines Flugzeugs genannt. Der Pilot hie? "Emil". Hatte sich "Emil" verflogen, weil "Franz" als Beobachter einen falschen Kurs angegeben hatte, so hatte sich die Maschine verfranzt. 由航空⽤语转化⽽来。
OpenGL读取,使用.vert.frag着色器文件C++
OpenGL读取,使⽤.vert.frag着⾊器⽂件C++本⽂作⽤: 写⼀个读取OpenGL⾥⾯ .vert .frag 这些⽂件的读取器。
读取函数代码://.frag .vert⽂件读取char* readTheFile(string strSource) {//fstream 中判断是否成功打开⽂件//https:///fruitz/article/details/41624921std::ifstream myfile(strSource);//打开失败if (myfile.fail()) {std::cout << "Can not open it " << std::endl;throw new runtime_error("IO stream corrupted");}//转换成字符串std::string str((std::istreambuf_iterator<char>(myfile)),std::istreambuf_iterator<char>());//关闭⽂件处理器myfile.close();//str数组长度⼀定要 +1,/*原因: https:///ShiQW5696/article/details/80676290 */int len = str.length();char* result = new char[len];strcpy_s(result, len + 1, str.c_str());return result;}另⼀种的着⾊器 Shader类管理⽅法(读取⽅法类似)完整测试代码:vertexShaderSource.vert#version 330 corelayout(location = 0) in vec3 aPos;OpenGLDemo.cpp// OpenGLDemo.cpp: 定义控制台应⽤程序的⼊⼝点。
Vue中fragment.js使用方法详解
Vue中fragment.js使⽤⽅法详解⼤部分内容源⾃ jQuery,当然,同时也参考了 component/domify ,如果有兴趣去这翻阅原始的代码,可以到 jQuery 中查找 wrapMap;⾄于domify,直接到 github 搜索即可,相关项⽬类容很少,直接看 index.js 就⾏了。
createDocumentFragment如果要在⼀个节点上⼀次性插⼊多个元素怎么办,⽐如说⼀次插⼊ 10000 个节点?最简单粗暴的⽅式就是:var parent = document.getElementById('parent');for(var i = 0; i < 10000; i++) {var child = document.createElement('div');var text = document.createTextNode('' + i);child.appendChild(text);parent.appendChild(child);}不过众所周知的原因,对 DOM 反复操作会导致页⾯重绘、回流,效率⾮常低,⽽且页⾯可能会被卡死,这段代码基本是没⼈⽤的。
如果分段来进⾏ DOM 操作呢,这样就能避免卡死页⾯了,js 忍者秘籍⾥⾯提到过可以⽤ setTimeout 来改进:var i = 0, max = 10000;setTimeout(function addNodes() {for(var step = i + 500; i < step; i++) {var child = document.createElement('div');child.appendChild(document.createTextNode('' + i));div.appendChild(child);}if(i < max) {setTimeout(addNodes, 0);}}, 0);当然,更多能想到的⽅式应该是,在内存中直接操作节点,所有节点都凑在⼀起之后再跟 DOM 树进⾏交互,把所有节点都串在⼀个 div 上,然后再把 div 挂到 DOM 树上:var parent = document.getElementById('parent');var div = document.createElement('div');for(var i = 0; i < 10000; i++) {var child = document.createElement('div');var text = document.createTextNode('' + i);child.appendChild(text);div.appendChild(child);}parent.appendChild(div);如上,只跟 DOM 树交互⼀次,性能⽅⾯肯定是⼤有改善的,不过额外插⼊了⼀个 div,如果说不是跟div之类的节点进⾏交互呢,⽐如在 table 中插⼊ th、td?这时候,createDocumentFragment 就该出马了,翻译过来叫“⽂档⽚段”,按MDN的描述:DocumentFragments 是⼀些 DOM 节点。
TOEFL VOCABULARY托福重点词汇大全
Below is a list of words that often appear on theTOEFL test. The underlined sections of a word provide links to definitions of that word's respective roots, prefixes and suffixes. Sentences are provided as examples of word usage.Aact, ag∙react (verb): to act in response to somethingo re + acto How did he react when he heard the news?∙agent (noun): something which acts or acts upon something elseag + ento The travel agent helped her purchase the tickets.∙active (adjective): involving movement, moving abouto act + iveo Joan is an active child.∙agitate (verb): to excite, to disturb, to stir upo agit + ateo The washing machine agitates the load of laundry.aud, audit, aur∙audible ( adjective): can be heardo aud + ibleo Your voice is barely audible over the sound of the train whistle.∙auditorium (noun): a place where one goes to hear somethingo audit+ oriumo The band played in the school auditorium∙auricularo aur + ic + ul + aro The auricular ability of the cat is well-known.am, ami∙amorous (adjective): lovingo amor + ouso The actor played an amorous role.∙amiable (adjective) friendly, agreeableo ami + ableo He seems to be an amiable man.∙amicable (adjective): friendlyo amic + ableo The two neighbors came to an amicable decision about the fence.anim∙animal (noun): a living creatureo anim + alo A dog is an animal.∙animate (verb): to give spirit or support, to supply movemento anim + ateo The artist animated the cartoon.∙animosity (noun): hostility, ill willo animos + ityo There isn't any animosity between us.ann, annu, enni∙annals (noun): record of events, historical recordso ann + al + so The annals of the organization are kept in notebooks.∙annual (adjective): yearlyo annu + alo She is planning on going to the company's annual meeting.∙annuity (noun): money payable yearlyo annu + ityo Joan is going to invest her annuity in the stock market.∙anniversary (noun): the yearly celebration of an evento anni + vers + aryo John's parents will celebrate their wedding anniversary in April.∙perennial (adjective): enduring, persisting for several yearso per + enn + ialo I would like to buy some perennial plants.auc, aug, aut∙author (noun): one that originates or creates, a writero auth + oro Susan met the author of this book.∙augment (verb): to increase, to add too aug + mento He had to augment his salary by taking another job.∙auction (noun): a sale of goods to the highest biddero auct + iono I bought this car at the auction.Bbene∙benevolent (adjective): marked by goodwillo bene + vol + ento The "Salvation Army" is known as a benevolent society for its acts of charity.∙benign (adjective): harmless, mild, gentleo ben + igno The doctor removed a benign tumor from my neck and I went home the same day. biblio∙bibliography (noun): a list of written workso biblio + graph + yo Olaf listed a brief bibliography at the end of his paper.bio, bi∙biology (noun): the study of lifeo bio + log + yo In biology class the students learned about how the human body works.brev∙brief (adjective): shorto briefo Anand gave a brief lecture on the rain forest.∙abbreviate (verb): to shorteno ab + brevi + ateo How does one abbreviate the word "Minnesota"?∙brevity (noun): short or concise expressiono brev + ityo The politician gave short speeches and he became known for his brevity.Ccad, cap, cas, ceiv, cept, cid∙deceive (verb): to cause or allow someone to believe something is true when it is actually false; to misleado de + ceiveo The criminal deceived many people into believing she was honest.∙capable (adjective): having the ability to do something; having the traits necessary to perform some actiono cap + ableo Jose is a very capable lawyer.∙capacious (adective): containing a great dealo capac + iouso You have a capacious library with many unusual books.∙captive (noun, adjective): a person held against his or her own will; held prisonero cap+ tiveo The captives were taken to the jail.o Geoff had a captive audience.∙accident (noun): an unplanned evento ac + cid + ento Don't get upset about minor accidents and errors.∙capture (verb): to gain control of, to gain by efforto capt + ureo In the game of chess, the object is to capture the king.∙occasion (noun): an opportunity; a happening, instance or celebrationo oc + cas + iono Did you have an occasion to speak with your professor?∙receive (verb): to take in, to acquireo re + ceiveo Imelda received many letters in the mail today.∙concept (noun): an ideao con + cepto The concept of using computers in the classroom is relatively new.ceas, cede, ceed, cess∙predecessor (noun): a person who has previously occupied a position that another has taken overo pre + de + cess + oro I hope I can live up to my predecessor's reputation.∙succeed (verb): to follow after another, to do wello suc + ceedo To succeed as a student, one must study.∙recede (verb): to move back, to withdrawo re + cedeo The water receded five days after the flood.∙concede (verb): to accept as true, to yield, to allowo con + cedeo I conceded to her point of view.∙exceed (verb): to go beyond a limit, to be greater thano ex + ceedo The driver exceeded the speed limit by ten miles an hour.∙recess (noun): an indentation, a temporary breako re + cesso The children were given a recess from the lessons.∙deceased (adjective): deado de + ceas + edo The deceased person will be cremated rather than buried.chron∙chronic (adjective): marked by a long period of time, recurrenceo chron + ico Gabrielle has a chronic back disorder and cannot lift heavy objects.∙chronicle (noun): a historical account arranged in order of timeo chron + icleo The teacher asked us to read a chronicle on the Revolutionary War.∙chronological (adjective): arranged in order of timeo chrono + log + icalo The text book listed the presidents in chronological order.clam, claim∙acclaim (verb): praiseo ac + claimo The restaurant is acclaimed for its desserts.∙exclaim (verb): to speak loudly, to cry out in surpriseo ex + claimo The children exclaimed "hurray" when they heard there would be no classes tomorrow.∙clamor (noun, verb): n. noise, v. to make noiseo clam + oro The children clamored for more ice cream.∙proclaim (verb): to declare loudlyo pro + claimo The president of the university proclaimed March 21 to be a holiday in honor of theschool's award winning faculty.cogn, gnos∙cognizant (adjective): awareo cogniz + anto The man was cognizant of the danger of walking through the park at night.∙diagnose (verb): to recognize (diseases) by symptomso dia + gnoseo The patient was diagnosed with Lyme's disease.∙agnostic (noun): one who believes that any ultimate reality is unknowableo ag + gnost + ico John is unsure of the reality of god and considers himself to be an agnostic.∙recognize (verb): to know, to identifyo re + cogn + izeo I thought I recognized your face from somewhere.corp∙corpse (noun): a dead bodyo corpseo A corpse was found floating in the river.∙corpulent (adjective): having a large bodyo corp + ul + ento The corpulent politician jabbed a fat finger in the air.∙incorporate (verb): to unite into one beingo in + corp + or + ateo The artist incorporated paint, photographs, and fabric into her artwork.∙corporate (adjective): formed into a body or association, united in one groupo corp + or + ateo The corporate structure allowed many people to work as a group.cre, cresc, cret∙crescent (noun, adjective): a narrow curved shape; a quarter moon or smallero cresc + ento The crescent moon could be glimpsed through the clouds.∙create (verb): to originate, to produce through imaginationo cre + ateo The musician created a new musical arrangement.∙accretion (verb): growth by gradual additiono ac + cret + iono The accretion of dirt on windows is sometimes hard to detect.∙increase (verb): to grow in size or amounto in + crease Alfonse wishes he could find a way to increase his salary.cred∙credible (adjective): can be believed, reasonableo cred + ibleo The witness gave a credible account of the accident.∙credulous (adjective): too ready to believeo cred + ul + ouso The credulous child believed the story about flying horses.∙incredible (adjective): unbelievable, amazingo in + cred + ibleo Makiko said she just saw an incredible horror movie.cour, cur, curr, curs∙excursion (noun): a tripo ex + curs + iono The father planned an excursion to the zoo for his children.∙discourse (noun, verb): a conversation, to talko dis + courseo The discourse between the speaker and the audience was informal.∙courier (noun): a messengero couri + ero The courier gave the message to the secretary.∙course (noun, verb): forward movement, movement from point to point; to run along a path o courseo Blood courses through your veins with every beat of your heart.∙occur (verb): to happen, to come to mindo oc + curo It just occurred to me that tomorrow is your birthday.∙current (adjective, noun): happening now, up to date; the movement of watero curr + ento Is this information current or out of date?Ddic, dict, dit∙dictionary (noun): a book of definitionso dict + ion + aryo Juliana looked up the word in the dictionary.∙condition (noun): the state of something or someoneo con + dit + iono Is your car in good condition?∙indicate (verb): to show, to point outo in + dic + ateo The gas gauge indicates that we are almost out of gas.∙dictate (verb): to speak for a person to record, to issue an ordero dict + ateo The lawyer dictated the letter to her secretary.∙predict (verb): to say what will happen in the futureo pre + dicto Joseph predicts that he will get married in ten years.∙addict (verb): to be devoted to something in an obsessive mannero ad + dicto Leslie is addicted to betting on the horse races.doc, doct∙doctor (noun): a person who has received the highest degree a university offers, a physician o doct + oro Andre is going to medical school so that he can be a doctor like his mother.∙doctrine (noun): something that is taught, dogmao doctr + ineo We learned about the doctrine of "manifest destiny" in our American history class.∙docile (adjective): obedient, easily taughto doc + ileo Mrs. Galindez wants to buy a docile dog for her son.∙document (noun): an official papero docu + mento The library houses many government documents in its collection.dog, dox∙orthodox (adjective): holding conventional beliefso ortho + doxo I don't know if my interpretation of that book is orthodox or not.∙dogma (noun): an established opiniono dog + mao Some people find the dogma associated with that organization disturbing.∙paradox (noun): a statement that seems to contradict itself but contains some trutho para + doxo The paradox of the matter is that I want to see the opera but I also want to stay home. dec, dign∙decorate (verb): to make something look attractive or suitableo dec + or + ateo Linda decorated her apartment with paintings and plants.∙decent (adjective): conforming to standards, good, kindo dec + ento This magazine contains a decent article on home improvement.∙dignity (noun): quality of being worthy, noble, honoredo dign + ityo I haven't yet had the dignity and honor of being grand marshall of the parade.duc, duct∙conduct (verb, noun): v. to lead or guide, n. a person's behavioro con + ducto Jared was conducted into the doctor's office by the nurse.o Arnelle's conduct was inexcusable and she should apologize to the class.∙educate (verb): to train, to provide schooling foro e + duc + ateo The school tries to educate its students to be productive members of society.∙induct (verb): to install in office or to enroll in military serviceo in + ducto Mindy was inducted into the army last month.∙deduct (verb): to subtracto de + ducto The salesperson deducted five dollars off the purchase price of the radio.∙deduce (verb): to make a decision or draw a conclusion by reasoningo de + duceo I deduced from the trail of crumbs and the empty milk carton that the children werehome.∙produce (verb, noun): to bring forward, to make to bear or yield; something made or grown o pro + duceo The lawyer produced new evidence at the trial.o The produce from the farm will go to the market next week.∙seduce (verb): to persuade (especially into doing something wrong), to tempto se + duceo Money and power have been known to seduce many honest people.∙induce (verb): to persuade, cause, or bring about by artificial means.o in + duceo If a child swallows poison, it is suggested that vomiting should be induced.Eev, et∙eternal (adjective): not effected by time, without beginning or end, ceaselesso etern + alo The lecture seemed eternal and many in the audience had fallen asleep.∙medieval (adjective): relating to the Middle Ages (500 - 1500 AD)o med + ievalo There are many styles to medieval architecture and a building built in 500 AD looksdifferent from one built in 1000 AD.Ffict, feign, fain∙faint (adjective, verb): indistinct, not clearly perceived, weak; to lose consciousness from lack of blood to the braino fainto There is a faint odor of apples in this room.o Some people faint at the sight of blood.∙feign (verb): to pretendo feigno The child feigned illness in an attempt to avoid the test.∙fiction (noun): something produce from imagination, an invented storyo fict + iono The excuse Marvin just gave for not doing his homework is pure fiction.fig∙effigy (noun): a figure representing a disliked person.o e f + fig + yo The children made an effigy of their nasty neighbor.∙figure (noun): shape, pattern, drawingo fig + ureo The figure Louise drew on the paper looks nothing like an apple.∙figment (noun): a thing that does not exist, something made upo fig + mento Ghosts and monsters are figments of an active imagination.fac, fact, fec, fic, fas, fea∙fashion (noun, verb): the form of something, style; to give shape or form too fash + iono The current fashion is hair worn short.∙feasible (adjective): capable of being doneo feas + ibleo The engineer thought that building the bridge across the river was a feasible project.∙feature (noun, verb): the appearance or form of a person or object; to picture or portrayo feat + ureo Lisette's best feature is her eyes.∙factory (noun): a place where things are made or builto fact + oryo There is a boat factory near the river.∙difficult (adjective): hard to do, troublesome, hard to understando di + fic + ulto The test was difficult and I answered only eight of the ten questions.∙fact (noun): something known to be trueo facto It's a fact that the world is round.∙effect (noun): a change caused by something, a result, influenceo e + fecto The sun's effect on human skin is known to be harmful.fer∙fertile (adjective): productive, bearing or capable of bearing fruit in large quantitieso fert + ileo The land by the river is quite fertile and many crops are grown there.∙refer (verb): to classify within a general category, to send or direct to another sourceo re + fero The patient was referred to a physical therapist for additional treatment.∙infer (verb): to come to a conclusion from facts or ideas, to guesso in + fero Sometimes a reader has to infer from the facts presented in an article what the main idea is about.fid∙diffident (adjective): hesitant in acting, shyo dif + fid + ento The diffident student would not speak in front of the class.∙fidelity (noun): the quality of being faithful, accuracyo fid + el + ityo The fidelity of this video reproduction is quite good.∙confide (verb): to trust, to trust another person with a secreto con + fideo Joan confided in her friend and told her a secret.flu, fluct, flux∙fluent (adjective): capable of moving with ease, able to speak another languageo flu + ento The dancer had a fluent body.o Juanita is fluent in several languages.∙superfluous (adjective): extra, more than is neededo super + flu + ouso Three cherries on my piece of cake is superfluous; I only needed one.∙influence (verb, noun): to have an effect on something; the ability to affect something indirectly o in + flu + enceo It was John's success as a musician that influenced my decision to take guitar lessons.∙fluid (adjective): capable of flowing, a smooth style, liquido flu + ido The ink my new pen is quite fluid and flows evenly across the page.∙fluctuate (verb): to shift back and forth, to move erraticallyo fluctu + ateo My body temperature has been fluctuating all day -- sometimes I'm hot and sometimes I'm cold.form∙format (noun): the shape and size of something, the arrangement of somethingo form + ato The format of this class will be half lecture and half class participation.∙formulate (verb): to prepare from a set of steps (formula), to deviseo form + ul + ateo The chemist formulated a new way of making dish detergent.fract, frag, frai∙fracture (verb, noun): to break, to crack; a broken boneo fract + ure Miguel fractured his arm while skiing.∙fragment (noun): a piece broken off, a part of somethingo frag + mento It bothers me that I can remember only a fragment of the poem rather than the wholepiece.∙frail (adjective): easily broken, not strongo frailo Be careful! That chair is frailGgen, gin∙generally (adverb): in a general manner, usually, with regard to the whole not specificso gen + er + al + lyo Generally, Lance leaves work at 5:00 p.m.∙gingerly (adverb, adjective): carefulo gin + ger + lyo Paulette picked up the antique vase gingerly and placed it on the shelf.∙indigenous (adjective): native, having been born in a specific area or environmento in + di + gen + ouso The tomato plant is indigenous to South America.ge∙geography (noun): a science that describes the earth's surfaceo geo + graph + yo The geography of New York varies from the sandy shores to rocky mountains.gor∙categorize (verb): to place things in classes or sets, to classifyo cate + gor + izeo The professor asked her students to categorize the plants they found.grad, gress, gree∙grade (noun): a stage in a process, a mark indicating qualityo gradeo Ali hopes to receive a passing grade on his midterm exam.∙progress (verb, noun): to move forward; forward movemento pro + gresso Mina progressed to the next level in her French language program.o There hasn't been much progress made in getting the house built -- only the frame is up.∙degree (noun): a step or stage in a process, a rank, a level of intensityo de + greeo There is a high degree of stress associated with being a police officer.graph, graf∙graphic (adjective): written, drawn, vividly showno graph + ico Dominic is planning to study graphic art.∙graffitti (noun): drawings or writing on a wallo graph + ittio Many people find the graffitti on the subway trains disturbing.Hher, hes∙adhere (verb): to sticko ad + hereo Paper often adheres to wet surfaces.∙hesitate (verb): to hold back a decision, to wavero hesit + ateo Don't hesitate to call me if you need help.Jjac, ject, jet∙adjacent (adjective): to lie next too ad + jac + ento You won't have a long walk between classes because the engineering building isadjacent to the chemistry laboratories.∙jettison (verb): to throw away, to cast offo jett + isono The captain of the sinking ship jettisoned the cargo.∙reject (verb): to throw out, unwilling to accepto re + jecto David was rejected by two schools before he found a school that accepted him. jug, junct, just∙adjust (verb): to change or adapt to fit or match somethingo ad + justo Jared has to adjust to his new work schedule.∙conjugal (adjective): of marriage, marital relationshipo con + jug + alo One should think seriously before entering a conjugal relationship.∙junction (noun): the place at which two things joino junct + iono Deborah's house is at the junction of Hill and Maple streets.Llex, leg∙college (noun): a school for higher learning, a group of people having a common purpose o col + legeo Yolanda is going to college to become a lawyer.∙legal (adjective, noun): based on law; conforms to lawo leg + alo Jared is working as a legal secretary for two lawyers in New Yorko Is it legal to own fireworks in Massachusetts or is there a law against them?∙league (noun): a group of people, an associationo leag + ueo There are fifty people participating in the bowling league.lect∙collect (verb): to gather, to bring togethero col + lecto The little girl collected wildflowers for her mother.∙legible (noun): readible, clear enough to reado leg + ibleo His handwriting is quite legible.∙eligible (adjective): qualified, worthy to be choseno e + lig + ibleo Now that Geoffrey is eighteen he is eligible to vote.loc∙locally (adverb): nearby, relative to a certain areao loc + al + lyo The vegetables are grown locally.log∙logic (noun): the study of reasono log + ico Simone is taking a class in logic and she is learning about how to reason.luc∙translucent (adjective): allowing some light to shine througho trans + luc + ento The sheet of paper is translucent when held close to a lightbulb.∙illuminate (verb): to provide with light, to make lighter, to make clearo il + lum + in + ateo The lamp illuminates the room.∙illustrate (verb): to explain by using pictorial examples, to show by using visual exampleso il + lustr + ateo Christopher illustrated his idea on piece of paper for everyone to see.Mman∙management (noun): the act of handling or running something, usually a business.o man + age + mento This store is under new management.mem∙commemorate (verb): to remember an important event through ceremony or observationo com + mem + or + ateo The American Revolution is commemorated every Fourth of July.∙memory (noun): the ability to recall past eventso mem + or + yo Geanine has an excellent memory and she can recall things that happened years ago. ment∙mental (adjective): related to the mindo ment + alo Lauren's mental abilities must be quite good if she achieved a perfect score withouteven studying.∙mention (verb): to cite, to speak about, to refer too ment + iono The instructor forgot to mention that the class was cancelled.min∙minor (adjective): lesser, less importanto min + oro The knife slipped and Marcelle received a minor cut.∙minute (adjective, noun): tiny, very small; sixty secondso min + uteo Even though the speck of dirt on the camera lens was minute, it ruined the photograph.o Terry will be finished in one minute.∙minuscule (adjective): very smallo minusc + uleo The minuscule gem was very hard to see without magnifying glasses.mit, miss∙admit (verb): to accept, to confess, to allow entryo ad + mito I must admit that even though you didn't like the movie I did.∙missive (noun): a letter to be sento miss + iveo Missives were more common one hundred years ago. Today, people use thetelephone.mob, mov, mot∙remove (verb): to take off or to take awayo re + moveo The waiter removed the dirty dishes from the table.∙mobile (adjective): able to moveo mob + ileo Many people drive their mobile homes from North to South, following the warmweather.∙motion (noun): act of moving, actiono mot + iono Many people find the motion of a rocking chair soothing.Nnasc, nat, gnant, nai∙native (adjective): belonging to a place by birth, indigenouso nat +iveo Turkeys are native to North America.∙nascent (adjective): just borno nasc + ento The nascent kittens curled up with their mother.∙pregnant (adjective): having a child developing in the womb, "with child"o pre + gn +ento Linda's dog is pregnant and it will have its puppies in November.∙naive (adjective): lack of experience, not knowledgeable of the worldo nai + veo When Olivia went to New York ten year's ago she was naive, but now she is awell-seasoned traveler.nom∙nominate (verb): to name for officeo nomin + ateo Vittorio nominated Mary for class president.∙synonym (noun): a word with a similar meaning to another word in the same languageo syn + onymo The word "fair" is a synonym for the word "just."nov∙novelty (noun): something newo novel + tyo After six months the novelty of Pierre's new car is starting to wear off.∙novice (noun): a newcomer, a beginner, someone new to somethingo nov + iceo Bjorn is a novice when it comes to playing poker or other card games.Ooper∙operate (verb): to work, to performo oper + ateo People are advised not to operate heavy machinery after drinking alcohol.∙opus (noun): a musical compositiono opuso Vivaldi's opus number three is not as well known as is other compositions.Ppat∙patient (adjective, noun): calm, bearing pain without complaint; a person under medical care o pati + ento Josiah was patient as he waited in line for concert tickets.∙passion (noun): a strong feeling or emotiono pass + iono Barbara has a passion for motorcycle racing.∙sympathy (noun): sharing another person's feelings, the ability to feel for another person's sufferingo sym + path + yo Ching-wei expressed his deepest sympathy when hearing of Mrs. Martin's death.∙pathology (noun): the study of diseaseso patho + log + yo Blaise is studying pathology because he wants to learn about diseases.ped∙impede (verb): to hinder, to slow downo im + pedeo The shackles and chains impeded the prisoner's escape.∙pedestal (noun): a support for a column or other structure, a base for somethingo pedest + alo Johannes put the vase on a pedestal.∙pedestrian (noun): a person walkingo pedestr + iano As soon as the cars stopped, the pedestrians crossed the street.pod∙podium (noun): a platform, an area raised above the surrounding ground, a place at which to speak in front of an audienceo pod + iumo The professor walked up to the podium and spoke into the microphone.pel∙repel (verb): to drive away or push backo re + pelo Does Margo's new jacket repel water?∙pulse (noun): the regular action of blood through arterieso pulseo The nurse felt for the patient's pulse in his neck.pend, pond∙suspend (noun): to hang from, to interrupt, to stopo sus + pendo The light was turned on by a string suspended from the light fixture.∙ponder (verb): to think about, to weigh in one's mindo pond + ero Levi pondered the possibility of going to medical school.phan, fan∙phantom (noun): something seen but having no physical existence, a ghost.o phan + tomo The children told horror stories about phantoms and ghosts.∙fantasy (noun): a creation of the imagination that cannot be real, a daydreamo fantas + yo When Miguel was a child he had a fantasy about being a doctor on the planet Jupiter.。
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自从Android 3.0中引入fragments 的概念,其上的是为了解决不同屏幕分辩率的动态和灵活UI设计。
fragments 的设计不需要你来亲自管理view hierarchy 的复杂变化,通过将Activity 的布局分散到frament 中,可以在运行时修改activity 的外观,并且由activity 管理的back stack 中保存些变化。
每一个fragments 都有自己的一套生命周期回调方法和处理自己的用户输入事件。
对应生命周期可参考下面流程:
onAttach()->onCreate()->onCreateView()->onActivityCreated()->onStart( )->onResume()此时Fragment就开始运行了。
onPause()->onStop()->onDestoryView()->onDestory()->onDetach()此时Fragment就彻底销毁了。
Fragment生命周期图如下:
其中onAttach()和onDetach()用的不是很多,而onCreateView()和onDestoryView()是Fragment生命周期和Activity生命周期不同的。
其他的可以按照Activity生命周期去理解。
下面补充一下Activity的生命周期。
三种系统内置的Fragments
系统内置了三种Fragments ,这三种Fragments 分别有不同的应用场景分别为:DialogFragment
对话框式的Fragments,可以将一个fragments 对话框并到activity 管理的fragments back stack 中,允许用户回到一个前曾摒弃fragments.
ListFragments
类似于ListActivity 的效果,并且还提供了ListActivity 类似的onListItemCLick和setListAdapter等功能。
PreferenceFragments
类似于PreferenceActivity .可以创建类似IPAD的设置界面。
有2种方法你可以添加一个fragment到activity layout:
一、在activity的layout文件中声明fragment
你可以像为View一样, 为fragment指定layout属性(sdk3.0以后).
例子是一个有2个fragment的activity:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="/apk /res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:name="com.example.news.ArticleListFragment"
android:id="@+id/list"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" /> <fragment
android:name="com.example.news.ArticleReaderFragment"
android:id="@+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
<fragment> 中的android:name 属性指定了在layout中实例化的Fragment类.
当系统创建这个activity layout时, 它实例化每一个在layout中指定的fragment,并调用每一个上的onCreateView()方法,来获取每一个fragment的layout. 系统将从fragment返回的View 直接插入到<fragment>元素所在的地方.
注意: 每一个fragment都需要一个唯一的标识, 如果activity重启,系统可以用来恢复fragment(并且你也可以用来捕获fragment来处理事务,例如移除它.)
有3种方法来为一个fragment提供一个标识:
为android:id 属性提供一个唯一ID.
∙为android:tag 属性提供一个唯一字符串.
∙如果以上2个你都没有提供, 系统使用容器view的ID.
二、使用FragmentManager将fragment添加到一个已存在的ViewGroup.
当activity运行的任何时候, 都可以将fragment添加到activity layout.只需简单的指定一个需要放置fragment的ViewGroup.为了在你的activity中操作fragment事务(例如添加,移除,或代替一个fragment),必须使用来自FragmentTransaction 的API.
可以按如下方法,从你的Activity取得一个FragmentTransaction 的实例:
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
然后你可以使用add() 方法添加一个fragment, 指定要添加的fragment, 和要插入的view.
ExampleFragment fragment = new ExampleFragment();
fragmentTransaction.add(R.id.fragment_container, fragment);
mit();
add()的第一个参数是fragment要放入的ViewGroup, 由resource ID指定, 第二个参数是需要添加的fragment.一旦用FragmentTransaction做了改变,为了使改变生效,必须调用commit().。