北京工业大学-892-2010-真题
09-10概率统计试题答案
北京工业大学2009—2010年度第一学期 概率论与数理统计考试试卷（工类，A 卷）学号 姓名 得分一. 填空题(每空两分,共30分)1. 已知P(A ）=0.5，P(A ∪B ）=0.8，且A 与B 相互独立，则P(A-B ）= 0.2 , P(A B ⋃）= 0.8 。
2. 设随机变量X 服从参数是λ的泊松分布，且P(X=3)=2P(X=4），则λ= 2 ,P(X ＞1）= 1-3e -2。
3. 设连续型随机变量X 的概率密度函数为：⎩⎨⎧≤≤=其它,010,4)(3x x x f ，且P （X ＞a ）=P （X ＜a ），则a= 2-1/4。
4. 若随机变量X 和Y 相互独立，且有相同的概率分布则随机变量Z=max{X,Y}的概率分布V=min{X ，Y}的概率分布 U=XY 的概率分布5. 设随机变量X ～B （n ，p ），已知E （X ）=3，Var （X ）=2.4，则n= 15 ，p= 0.2 。
6. 设X 1，X 2，…，X n 为独立同分布的随机变量，且X 1～N （0，1），则∑=ni i X 12～2n χ。
E21n i i X =⎛⎫ ⎪⎝⎭∑= n 。
Var 21n i i X =⎛⎫⎪⎝⎭∑= 2n 。
7. 设X 1，X 2，X 3是正态总体2(,)N μσ的随机样本，其中μ已知，2σ未知，在)(1),,,max(,2),(3121222123211321X X X X X X X X X X +++++σμ中，是统计量的有 ),,,max(,2),(313211321X X X X X X X μ+++8. 已知一批零件的长度X （单位：cm ）服从正态分布N （μ，1），从中随机抽取16个零件，得到长度的平均值为40cm ，则μ的置信系数为0.95的置信区间为2ασZ nX。
二、计算题（每题14分）注意：每题要写出计算过程，无过程的不得分！1. 钥匙掉了，掉在宿舍里、掉在教室里、掉在路上的概率分别是40%、35%和25%。
北京工业大学2010-2013学年数理统计与随机过程(研)试卷
北京工业大学2010-2011学年第一学期期末数理统计与随机过程(研) 课程试卷学号 姓名 成绩 注意：试卷共七道大题，请写明详细解题过程。
数据结果保留3位小数。
考试方式：半开卷，考试时只允许看教材《概率论与数理统计》 浙江大学 盛骤等编第三版（或第四版）高等教育出版社，不能携带和查阅任何其他书籍、纸张、资料等。
考试时允许使用计算器。
考试时间120分钟。
考试日期：2011年1月4日1.某茶叶制造商声称其生产的一种包装茶叶平均每包重量不低于150克，已知茶叶包装重量服从正态分布，现从一批包装茶叶中随机抽取100包，经计算得到样本均值为149.7,样本标准差为0.9,试在α＝0.01的显著性水平上检验该制造商的说法是否可信？2. 某食品市场的经理将根据预期到达商店的顾客来决定职员分配数目以及收款台的数目。
为检验工作日上午顾客到达数（用5分钟时间段内进入商店的顾客数来定义）是否服从泊松分布，随机选取了一个由3周内工作日上午的128个5分钟时间段组成通过这些样本，请你帮忙分析到达顾客数服从泊松分布吗？（取显著性水平）3.一家关于MBA 报考、学习、就业指导的网站希望了解国内MBA 毕业生的起薪是否与各自所学的专业有关，为此，他们在已经在国内商学院毕业并且获得学位的MBA 学生中按照专业分别随机抽取了5人，调查了他们的起薪情况，数据如下表所示（单 位： 万元），根据这些数据他们能否得出专业对MBA 起薪有影响的结论？（取显著性水平050.=α）4．为定义一种变量,用来描述某种商品的供给量与价格之间的相关关系.首先要收集（1） 试确定（2） 对回归方程进行显著性检验（α=0.05）；（3） 当x=20时,求y 的95％的预测区间。
5．6．设{,}n X n T ∈是一个齐次马尔可夫链，其状态空间{0,1,2}I =，其一步转移概率矩阵为 3104411142431044P ⎛⎫ ⎪ ⎪= ⎪ ⎪ ⎪⎝⎭其初始状态的概率分布为01(0)(),0,1,2,3i i p P X i i ====求： （1）求2{1}P X =；（2）求2{2|1}n n P X X +==；（3）求012{1,2,1}P X X X ===；（4）讨论此链是否具有遍历性，若是遍历的求其极限分布。
北京工业大学数学分析2010年考研真题(含答案)考研试题硕士研究生入学考试试题
十、 解：补充平面 S1 = {( x, y, z ), x 2 + y 2 ≤ 1，z = 1}，方向向上.有
∫∫
=
f ( x , y ) 在原点处不可微。
共 6 页 第4 页（答案）
科目代码：
663
科目名称：
数学分析
2 2 七、 解： 上、 下半圆方程分别为 y1 = 2 + 1 − x 与 y2 = 2 − 1 − x .
旋转体体积 V = 旋转体表面积
∫
1
−1
2 π [ y12 - y2 ] dx = 8π ∫
收敛，求其极限。
[bx − f ( x)] = 0 ，其中 二、 证明：若函数 f ( x ) 在 [a, +∞) 上连续，且 xlim →+∞
b 为非零常数，则 f ( x ) 在 [a, +∞) 上一致连续。
三、 证明：若 ∀x ∈ (a，b) ，有 f ′′( x ) ≥ 0 ，则对 ∀x1 , x2 ,L , xn ∈ ( a, b ) ， 下列不等式成立
当 | x1 − x2 |≤ δ1 =
ε 时，有 2|b|
| f ( x1 ) − f ( x2 ) |≤ b( x1 − x2 ) + bx1 − f ( x1 ) + bx2 − f ( x2 ) < ε.
其次，由 f ( x ) 在 [a, +∞) 上连续，知 f ( x ) 在 [ a , M + 1] 上连续且一 致连续。于是，对上述的 ε > 0 ，存在 δ 2 > 0 ，当 ∀x1 , x2 ∈ [a, M + 1] ，
| x1 − x2 |≤ δ 2 时，有 | f ( x1 ) − f ( x2 ) |< ε .
2010年北京面试真题
2010年北京11.28号下午面试题目答案1．现在很多地方热衷于申报非物质文化遗产，引起群众不满，你怎么看？【试题分析】此试题属于综合分析题，考察考生的综合分析能力，此题的重点在于对此事件的原因的分析是否深入到位及相关对策建议是否具有可行性。
考生对原因分析和出现的主要问题可能是难点，可使用主体分析法，分析地方热衷申报的原因和群众不满的原因。
【解题思路】首先，了解什么是非物质文化遗产，对于申报非物质文化遗产的作用；其次，分析地方热衷申报的原因和群众不满的原因及出现的主要问题，最后，针对原因分析改善这种现状的方法。
【参考答案】非物质文化遗产是活着的文化遗产，是保证文化多样性与人类创造性的关键所在。
非物质文化遗产就其本质来说，它是我国民族的知识体系当中的一部分非常重要的宝贵财富。
它凝结着我们的历史记忆，它既是昨天历史的、生活的实录，同时也是我们今天生活的现实，对于未来的文化发展来说，也是一个非常重要的基础。
申报非物质遗产可以防止在迅速前进的社会中丢掉自己的文明，保护我国的五千年的民族文化。
但现在很多地方对于非物质文化遗产的申报并不是从本地的实际文化出发，首先地方政府千方百计将“申报”和旅游挂钩，只要申报成功，旅游的成本就必然增加，其次，申报更多的是和政绩或商业利益结合在一起，没有把文化真正保护起来。
群众对准备申遗要涨价，申遗成功更要涨价，和政府重申报、轻保护；重开发利用，轻深入研究；重经济效益，轻文化内涵；重一时举措，轻长期规划的这些问题也越来越不满。
那针对于我国地方政府对物质文化遗产申报和保护工作存在的这些误区，我认为首先是政府保护，除了正在完善的法律之外，还有国家对“非遗”的认定，认定之后政府会对传承人有一定的支持；第二是专家保护，帮助政府和社会认识到非遗的意义；第三，城市建立了“非遗”保护的博物馆，把保护工作持续进行下去。
所以，政府和群众都要认识到非物质文化遗产保护工作的重要性和迫切性，地方政府需量力而行。
北京交通大学942真题2010(最新整理)
北京交通大学942管理运筹学2010年真题一.(24分)判断（正确的打“√”错误的打“×”）（1）线性规划问题的每一个基解对应可行域的一个顶点；x（1），x（2）分别是某一线性规划问题的（2）若最优解，λ1x（1）λ2x（2）则x=+也是该线性规划问题的最优解，其中λ1，λ2为正的实数；y∗1y∗1（3）已知为线性规划的对偶问题的最优解，若>0，则说明在最优生产计划中第i种资源已完全耗尽；（4）整数规划问题最优解的目标函数值一定优于其相应的线性规划问题最优解的目标函数值；（5）指派问题效率矩阵的每个元素乘以同一大于0的常数k，将不影响最优指派方案；（6）如果图T是树，则T中一定存在两个顶点，它们之间存在两条不同的链；（7）任一图G=（V,E）都存在支撑子图和支撑树；（8）网络图中任何一个结点都表示前一工序的结果和后一工序的开始；（9）结点最早时间同最迟时间相等的点连接的线路就是关键线路；（10）假如到达排队系统的顾客为普阿松流，则依次到达的两名顾客之间的时间间隔时间服从负指数分布；（11）运输问题是一种特殊的线性规划模型，因而其求解结果也可能出现下列四种情况：唯一最优解，无穷多最优解，无界解，无可行解；（12）单纯形法计算中，选取最大正检验数对应的变量作为换入变量，将使目标函数得到最快的增长。
二．简答（1）试简述求解整数规划模型的分支定界法剪枝的几种情况；（6分）（2）试写出标准指派问题的线性规划模型；（4分）（3）试写出求解最短路径的Dijkstra算法的步骤；（6分）（4）试写出M/M/1排队系统的Little公式。
（4分）三（40分）某厂生产Ⅰ，Ⅱ，Ⅲ三种产品，其所需劳动力，原材料等有关数据如下：每件产品Ⅰ分别需要劳动力和原材料为6小时和3公斤，每件产品Ⅱ分别需要劳动力和原材料为3小时和4公斤，每件产品Ⅲ分别需要劳动力和原材料为5小时和5公斤；拥有的劳动力和原材料总数分别为45小时和30公斤；又已知Ⅰ，Ⅱ，Ⅲ三种产品的单件利润分别为3,1,4元。
北工大895历年真题答案
问题：用 malloc 函数开辟的空间没有用 free 函数回收。 2. (1) 算法用途：求输入文本的最长行 输入:从键盘读入多行文本（以空行结尾） 输出:所有最长行及其行号（可能有多个最长行） (2) 代码(亲测可用，附截图)
#include "stdafx.h" #include<stdlib.h> #include <stdio.h> #include<string.h> typedef struct node { // 缓冲区链表 char line[ 256 ]; int num; struct node *next; } Link; Link * addlink ( Link *p, char *line, int i ) { Link *q = (Link *)malloc( sizeof( Link ) ); strcpy( q->line, line ); q->num = i; q->next = p; return q; // 在表头添加元素 }
//树结点的数据类型，暂定为整形 //孩子结点
//表头结构
//树结构 //结点数组 //根结点的位置和结点数
/*树的孩子兄弟表示法结构定义 */ typedef struct CSNode { ElemType data; struct CSNode *firstchild, *rightsib; }CSNode, *CSTree;
typedef struct { PTNode nodes[MAXSIZE]; //结点数组 int r,n; //根的位置和结点数 }PTree; /*树的孩子表示法结点结构定义 */ #define MAXSIZE 100
北京工业大学自动控制原理 期末试题及答案
《自动控制原理》期末试卷答案（A ）北京工业大学 电控学院 日期：2005年12月25日大题 一 二 三 四 五 六 七 八 九本题 分数 10 10 10 10 10 10 10 1515 本题 得分一、（10分）已知有源电网络如图所示。
由复数阻抗法求传递函数)()(0s U s U i 。
解： 211()R Cs G s R Cs+=−二、（10分）已知输入前馈系统的结构图如图（a ）所示，要求保证闭环传递函数不变的前提下将输入前馈结构变换成输入补偿结构如图(b )所示 ，试确定输入补偿器传递函数()f G s 。
（a）(b)解 114.0)(+=s s G f三、(10分) 设系统结构如图所示，试计算系统单位阶跃响应时的超调量M p 和过渡时间s t 。
解：系统闭环传函为2100()10100C G s s s =++2100,10n n ωω==210,0.5n ζωζ==，p s 4100%16.3%,0.8nM e t ζω=×===四、（10分）已知系统结构图如图所示，试写出闭环传递函数，并计算输入信号为()0.5r t t =时的稳态误差。
解：（1）系统闭环传递函数为c 25(0.21)()0.055s G s s s +=++（2） ss c 2000.5lim ()lim [1()]s s e sE s s G s s→→==−222220050.50.050.5lim [1]lim 00.0550.055s s s s s s s s s s s s→→+=⋅−⋅=⋅⋅=++++五、（10分）已知系统结构图如图所示，试作系统的根轨迹草图。
解：1、起点 sq1=0，sq2= -5， sq3=-102、终点 sz1= sz2= sz3= -∞3、实轴根轨迹 [0 -5]， [-10 -∞]4、分离点321550K s s s =++，2330500dKs s ds=++=，7.89(), 2.11s =−−舍5、渐近线180(21)60,180k n m θ±+==±±−D D D 1553p z n m σ−=−=−=−−∑∑ 6、虚轴交点3215500s s s K +++= 15015750KK K−750,7.07K ω===±六、（10分）二阶线性定常系统的微分方程为20x xx +−= 试确定该系统的奇点以及奇点类型。
北京工业大学环工专业英语考试真题
北京工业大学环工专业英语考试真题全文共3篇示例，供读者参考篇1Beijing Industry University Environmental Engineering Major English ExamPart I: Reading Comprehension (50 points)Directions: There are four passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the center.Passage 1: Global WarmingGlobal warming is one of the most significant environmental issues facing the world today. It refers to the gradual increase in the Earth’s temperature due to huma n activities, such as the burning of fossil fuels and deforestation. The consequences of global warming include rising sea levels, changes in weather patterns, and the extinction of various species.1. What is global warming?A. A decrease in the E arth’s temperature.B. An increase in the Earth’s temperature due to human activities.C. A natural phenomenon.D. A result of volcanic eruptions.2. What are the consequences of global warming?A. Decreasing sea levels.B. Stable weather patterns.C. Extinction of species.D. Healthy ecosystems.Passage 2: Environmental PollutionEnvironmental pollution is the introduction of harmful substances into the environment that can cause harm to humans, wildlife, and the ecosystem. Common sources of pollution include industrial activities, vehicle emissions, and improper waste disposal. To combat pollution, it is essential to implement strict regulations and promote sustainable practices.3. What is environmental pollution?A. The conservation of natural resources.B. The introduction of harmful substances into the environment.C. The promotion of industrial activities.D. The protection of wildlife.4. How can pollution be reduced?A. By increasing industrial activities.B. By implementing strict regulations and promoting sustainable practices.C. By cutting down forests.D. By increasing vehicle emissions.Part II: Listening Comprehension (20 points)Directions: This part is composed of four sections. In each section, you will hear a dialogue or a monologue. After listening to it, you are required to complete some unfinished statements or answer some questions. You are allowed to hear the recording only once.Section A5. What is the lecture mainly about?Section B6. What is the man’s problem?Section C7. Why does the woman want to change her major?Section D8. What suggestion does the man give to the woman?Part III: Writing (30 points)Directions: For this part, you are required to write an essay on the following topic: "The Importance of Environmental Education." You should write at least 200 words and make sure to use proper grammar and vocabulary.Remember to discuss the significance of environmental education in raising awareness about environmental issues and promoting sustainable practices._____This is the sample of a Beijing Industry University Environmental Engineering Major English Exam. Students are required to demonstrate their understanding of key environmental concepts and their ability to communicate effectively in English. Good luck with your exam preparation!篇2Beijing University of Technology Environmental Engineering Major English Exam QuestionsPart I: Reading ComprehensionRead the following passage and answer the questions that follow.Over the past few decades, the issue of climate change has become a major concern for many countries around the world. The increase in greenhouse gases in the atmosphere, mainly caused by human activities, has led to rising global temperatures and extreme weather events. In response to this crisis, many nations have come together to sign international agreements aimed at reducing emissions and slowing down the effects of climate change.1. What is the main cause of rising global temperatures?2. What are some of the effects of climate change?3. What are some international agreements that have been signed to address climate change?Part II: VocabularyChoose the correct word to complete each sentence.1. The __________ of carbon dioxide in the atmosphere has been steadily rising.A) concentrationB) consumptionC) conservationD) contamination2. The government has implemented strict __________ to reduce air pollution in the city.A) regulationsB) renovationC) recreationD) rejuvenation3. The Environmental Protection Agency is responsible for monitoring and enforcing laws related to environmental__________.A) pollutionB) preservationC) protectionD) provisionPart III: GrammarChoose the correct verb form to complete each sentence.1. The students __________ (study) for their exams all week.A) have been studyingB) had studiedC) will studyD) were studying2. By the time we get to the beach, the sun __________ (set) and it will be dark.A) will setB) is settingC) has setD) will have set3. I wish I __________ (know) more about renewable energy sources.A) had knownB) knewC) will knowD) have knownPart IV: WritingWrite a short essay (200-300 words) on the following topic:"Discuss the importance of environmental engineering in today's society. What are some of the key challenges facing environmental engineers, and how can they be addressed?"Remember to include an introduction, body paragraphs, and a conclusion in your essay. Use examples and evidence to support your ideas.Good luck with your exam!篇3Beijing University of TechnologyDepartment of Environmental EngineeringFinal ExamEnglish SectionInstructions:This exam contains three sections: Reading Comprehension, Vocabulary, and Writing. Please read the instructions carefully before starting the exam.Reading Comprehension (50 points)Read the following passage carefully and answer the questions below.The concept of sustainable development has gained increasing attention in recent years. It refers to the idea of meeting the needs of the present without compromising the ability of future generations to meet their own needs. This involves balancing economic growth, social progress, and environmental protection. Sustainable development requires a long-term perspective and a holistic approach todecision-making.1. What does sustainable development mean?2. What are the key elements of sustainable development?3. Why is sustainable development important?Vocabulary (30 points)Choose the correct word that best fits each sentence.1. The government has implemented _____ measures to reduce air pollution in the city.A) stringentB) lenientC) moderateD) severe2. It is important for industries to adopt _____ practices to minimize their impact on the environment.A) sustainableB) wastefulC) harmfulD) irresponsibleWriting (20 points)Write an essay of 300-400 words on the following topic:"The role of environmental engineers in promoting sustainable development."In your essay, discuss the responsibilities of environmental engineers in addressing environmental challenges andpromoting sustainable practices. Provide examples of projects or initiatives that have successfully contributed to sustainable development.End of ExamPlease submit your completed exam to your proctor. Good luck!Note: This exam is for evaluation purposes only. It will not affect your final grade in the course. Thank you for participating in the exam.---This document is a sample of a final exam for the Department of Environmental Engineering at Beijing University of Technology. Students are required to demonstrate their knowledge of sustainable development, environmental engineering principles, and English language skills in this comprehensive exam.。
北京工业大学信号与系统(822)硕士试题2010
t<0 ⎧ 0, ⎩e(t ) + e(t − 100), t ≥ 0
e(t )
d) r (t ) = π
8. 下列各系统中， x( k ) 表示激励信号， y (k ) 表示响应。那么下列哪个系统是线性、时不变性的 。 a) y (k ) = Kx (k ) + 3 c) y ( k ) = 4[x( k )]
Y (ω ) = X (ω − ωM ) , ω > 0 Y (ω ) = X (ω + ωM ) , ω < 0
1） 若 X (ω ) 的频谱如图 a 所示，试绘制加密后信号 y (t ) 的频谱；
X (ω )
−ωM − ω 1 0 ω 1
图a
ωM
ω
2） 试用放大器、乘法器、加法器、振荡器和你认为必要的任何类型的理想滤波器，设计满足题 目需求的理想加密器（给出设计框图） ； 3） 如同问题 2） ，设计满足题目需求的理想解密器（给出设计框图） 。
终值 x ( ∞ ) 分别为 a) 0，0 c) 0，-12 。 b) 2，0 d) 1，∞
共 9 页
第 3 页
科目代码：
822
科目名称：
信号与系统
★所有答案必须做在答题纸上，做在试题纸上无效！
二、填空题（每题 3 分，共 30 分） 请将试题编号及正确答案写在答题纸上
se −2 s + 1 11. X ( s ) = 的逆变换 x(t ) = ( s + 1)( S + 2)
共 9 页
第 1 页
科目代码：
822
科目名称：
信号与系统
★所有答案必须做在答题纸上，做在试题纸上无效！
4. 连续时间信号通过一个微分器，输出信号的频谱等于 a) 。
北京工业大学-2018年硕士研究生招生考试大纲-892软件专业基础综合
2018年硕士研究生招生考试大纲
考试科目名称：软件专业基础综合考试科目代码：892一、考试要求
软件专业基础综合考试大纲适用于北京工业大学信息学部（085212）软件工程（专业学位）的硕士研究生入学考试。
考试内容包含数据结构与算法，这门课程是软件工程学科的重要基础理论课。
考试内容主要包括数据结构的基本概念和术语、线性表、栈和队列、数组、串和广义表、树和二叉树、集合与字典、搜索结构、图和内部排序，要求考生对其中的基本概念有很深入的理解，掌握算法的设计及评价方法，具有综合运用所学知识分析问题和解决问题的能力。
二、考试内容
（一）数据结构的基本概念和术语
（1）掌握数据结构的基本概念和术语
（2）掌握数据结构的逻辑结构、存储结构
（3）熟练掌握抽象数据类型的表示方法
（4）熟练掌握算法的时间复杂度、空间复杂度的分析方法
（二）线性表
（1）掌握线性表的逻辑结构
（2）掌握线性表的顺序存储结构及插入删除、查找、遍历等操作的实现（3）掌握线性表的链式存储结构及插入删除、查找、遍历等操作的实现（三）栈和队列
（1）掌握栈的定义、栈的抽象数据类型及存贮表示
（2）熟练掌握栈操作的实现
（3）熟练掌握递归算法
（4）掌握队列的定义、队列的抽象数据类型及存贮表示
（5）熟练掌握队列操作的实现及应用
（四）数组、串和广义表
（1）理解数组的定义、存贮表示及应用。
北京工业大学环工专业英语考试真题
北京工业大学环工专业英语考试真题全文共6篇示例，供读者参考篇1My Big Summer AdventureHello teachers and friends! My name is Lily and I'm 8 years old. This summer I had the most exciting, amazing, incredible adventure ever! I went on a trip with my mom and dad to learn all about protecting the environment. We visited lots of different places and I saw so many cool things. I can't wait to tell you all about it!First we went to a recycling center. It was this huge building with big trucks bringing in bottles, cans, paper and all kinds of other stuff that people didn't need anymore. The workers there sorted everything into different piles. Then they smashed up the plastic, metal and glass into tiny pieces so it could get melted down and reused to make new bottles, cans and jars. Isn't that neat?My favorite part was watching the giant machine chomp up all the cardboard boxes. It was so loud but really fun to see. The guy working the machine let me push the button to start it up.He said recycling helps save trees because we don't have to use as much new paper. I don't want any trees to get chopped down, so I always make sure to recycle! At home, we have different bins for bottles, paper, and regular trash. Taking care of the planet is easy when you recycle.After the recycling center, we visited a landfill site. That's where all the trash goes that can't get recycled. I didn't like it there as much because it smelled really stinky! All the garbage gets buried in a huge hole in the ground. My dad said that's not good because it takes up space that could be used for parks or forests instead. And when things like food and plastic bags get buried, they make a bad gas that goes into the air we breathe. Yuck!The best part was going to the science museum. They had an whole exhibit about renewable energy like solar power, wind farms and hydroelectric dams. I got to run on a little treadmill that used my steps to power a light bulb! They also had bikes connected to a TV, so when you pedaled it would keep the cartoons playing. That was super cool.I learned that renewable energy sources don't pollute the air with bad gases like coal or natural gas power plants do. Wind turbines use the wind to make electricity without any smoke orfumes. And solar panels take energy directly from the sun's rays and turn it into power for our homes and electronics. Using clean energy is really important for having fresh air to breathe and a healthy environment.Another awesome thing I saw were all the different electric cars they had on display. They don't need gasoline and don't make any exhaust that dirties the air. My dad said pretty soon all our cars will probably be electric instead running on gas from oil.I got to pretend to drive one of the kid-sized electric cars. It was so much fun!On our last day, we hiked through a national forest and saw lots of different kinds of trees, plants, birds and animals. I loved being out in nature and breathing the fresh, clean air. Our guide taught us that the trees and plants are so important because they clean the air by taking in carbon dioxide and giving us oxygen to breathe.She said we need to protect forests and green spaces so we can have nice parks to play in and homes for all the cute critters like deer, rabbits, and squirrels. Cutting down too many trees and paving over everything with parking lots is bad for the environment and makes it harder to have nice clean air to breathe.After our hike, we had a picnic in a pretty meadow full of wildflowers. I got to run around and play while my parents talked to the guide some more about how we can all do better at taking care of the Earth. She said every little bit helps, like using less plastic, saving water and electricity, walking or biking instead of driving sometimes, and recycling as much as possible.My mom and dad promised we'll start doing more to go green at home. We're going to set up a compost bin in our backyard for our fruit and veggie scraps. Instead of throwing them in the trash, they'll decompose and become nutrient-rich soil for our garden. We're also going to take shorter showers, turn off lights we aren't using, and try to cut way down on single-use plastics that just get thrown out.I had so much fun learning about the environment on our trip. Now I understand way more about why it's so important to reduce, reuse and recycle. We've gotta take good care of our beautiful planet Earth so it can keep taking good care of us! The fresh air, clean water, plants, trees and animals are precious gifts we need to protect. I'm going to try my best to be an environmental superhero from now on.Thank you for reading my essay! I hopes it helps you learn about ways we can all go greener too. Let's work together tokeep our world healthy and clean for many more generations to come. The Earth is our one-and-only home, so we need to treat it with lots of love and respect. See you next time!篇2My Big Environmental Engineering TestHi friends! Today I have to tell you about the big important test I just took. It was an English exam for the Environmental Engineering program at the super famous Beijing University of Technology. I'm only in 5th grade, but I really want to study Environmental Engineering when I grow up because I care a lot about protecting the planet and all the plants and animals.My mom said I should practice taking this test because it would be good experience for me, even though I'm still just a kid.I wasn't too nervous though, because English is one of my best subjects and I'm already really interested in environmental issues.The first part of the test was reading comprehension. I had to read a few passages about things like air pollution, water scarcity, climate change, and deforestation. The passages used some pretty big words I didn't know, like "anthropogenic" and"mitigation strategies." But I could figure out the main ideas based on context clues.After reading each passage, I had to answer multiple choice questions testing how well I understood the key details and concepts. Those weren't too bad. Then there were someopen-ended questions where I had to write a few sentences explaining my thoughts on the topics. That part was kind of hard because I had to organize my ideas clearly in complete English sentences with good grammar.The next section was all about vocabulary. First, I had to fill in blanks to complete sentences and paragraphs with vocabulary words related to the environment and sustainability. Words like "emissions," "renewable," "biodiversity," and "ecological footprint." I've learned a lot of those from watching nature documentaries with my parents.Then I had to match vocabulary words with their definitions. That was a little trickier because some of the words had multiple meanings that were really similar. Like the difference between "pollutant" and "contaminant." Overall though, I think I did pretty well with vocabulary since it's one of my strengths.After vocabulary was the grammar section. Ugh, grammar! That's probably my worst skill when it comes to English. The testasked me to identify parts of speech, correct errors in sentences, and show my understanding of things like verb tenses, subject-verb agreement, and modifiers. Why does English have so many little grammar rules to memorize? My native language is so much simpler!There was also a writing task where I had to write a persuasive essay about an environmental issue that's important to me. I chose to write about single-use plastics and why we need to reduce plastic waste. I made sure to have a clear thesis statement, use lots of specific examples and evidence, and organize my argument into paragraphs with good transition sentences. Writing has always been one of my favorite parts of English because I get to express my own thoughts and be creative.The very last part was about interpreting data and information. I had to analyze some graphs and charts about things like greenhouse gas levels, renewable energy production in different countries, and endangered species populations. The questions asked me to describe trends, make inferences, and draw conclusions. I feel like I struggled a bit on those because math has never been my strongest area.Phew, that's everything I can remember about the test! It definitely covered a wide range of topics and skills related to environmental science and policy, all through the challenging lens of advanced English reading, writing, and comprehension. Even though it was just practice, I could see how this type of exam does a great job of testing whether students are prepared for the rigorous English communication and critical thinking required in an Environmental Engineering degree.I'm so curious to find out how I did! No matter what my score is though, I know the experience of taking a real university admissions test will help me a lot when I'm actually applying to colleges in the future. I want to do everything I can now to get ready to be an environmental engineer and make the world a cleaner, safer, more sustainable place for my generation and beyond. Wish me luck, friends! Let me know if you have any other questions about my big test day.篇3My Big Environmental Exam AdventureHi everyone! My name is Lily and I'm 8 years old. I just had the craziest day at school and I can't wait to tell you all about it!It started out as a normal Wednesday. I got up, got dressed, ate my breakfast of congee with pickled veggies (my favorite!), and headed off to Sunshine Elementary. When I got to class, my teacher Mrs. Wang told us we were all going to take a very special test. She said it was going to be super hard and only for the smartest kids. I got really nervous because tests always make me sweaty and shaky.Then Mrs. Wang said "Just kidding! You're all going on a field trip instead!" We were all so relieved. Field trips are way more fun than tests. She told us to get our sun hats and water bottles because we were going to Beijing University of Technology! I was very excited because I've never been to a real university before.We walked for what felt like forever before we finally made it. BUIT was so big! The buildings were huge and everything was green and pretty. Mrs. Wang led us to a building she called the "Environmental Engineering Department." I didn't know what that meant but it sounded very serious and important.An older student named Zhang Wei greeted us. He seemed very nice. "Hi everyone!" he said in a deep voice. "Welcome to the Environmental Engineering department. Today you're all going to get to take an actual university exam on篇4My Big Bro's Crazy Hard English TestHi there! My name is Little Wang and I'm 8 years old. I'm in 3rd grade and I go to Sunshine Elementary School. I love playing video games, reading comic books, and hanging out with my friends. But today I'm gonna tell you about something way less fun - my big brother's insanely difficult English exam!You see, my big bro Wang Dapeng is a student at the amazing Beijing University of Technology. He's studying to be an Environmental Engineer, which seems like a pretty cool job if you ask me. He gets to learn all about keeping our air and water clean, protecting animals and plants, and making sure the earth stays healthy. The only bummer is that he has to take a gigantic English test every year as part of his major.Last week, Dapeng was stressing hard about his upcoming English exam. He had these massive textbooks spread all over the living room floor. They were full of big weird words I've never even heard of, like "biogeochemical cycles" and "anthropogenic emissions." No joke, some of those words were longer than my full name! My bro was trying to memorize all the definitions and facts and formulas written in those books.I felt really bad seeing him so overwhelmed, so I asked him to explain to me what the test was all about. He said it covered every single topic related to Environmental Engineering, but it was 100% in English. No Chinese allowed at all! He had to be able write perfectly about complex scientific concepts using only English vocabulary and grammar. The test was broken into sections like:Air pollution analysisWater treatment solutionsSustainable energy sourcesClimate change mitigation strategiesEnvironmental policies and regulationsJust listening to Dapeng rattle off those section names made my head spin. He then showed me an actual question from a previous year's test. I could barely read it, it was written in such fancy-schmancy English:"Elucidate the thermodynamic and kinetic fundamentals underpinning catalytic converter functionality in mitigating atmospheric pollutants emanating from automotive exhaust systems. Provide substantive analysis regarding emergentinnovations aimed at augmenting pollutant remediation efficacy."I had no clue what any of那句子even meant! And poor Dapeng had to write a multi-paragraph academic essay responding to questions like that, using sophisticated technical jargon and citation of scientific literature. No wonder he looked so stressed!To make matters worse, the exam was timed and he only had a few hours to write out extensive explanations in English for a dozen complicated prompts. He couldn't use any notes or translation dictionaries either. It was an intense open-book test, but the "open book" was just thick textbooks and research papers...printed fully in English! No Chinese text was allowed as a reference.My bro worked day and night practicing his English writing skills. He did practice exams, attended tutoring sessions, and wrote sample essays that his professors would critique. Sometimes he would read portions out loud to me, and I would just blankly nod my head even though I didn't understand the majority of the words he was using.Finally, after weeks of hardcore preparation, the day of the big test arrived. Dapeng had to wake up at 6am and didn't returnhome until after 8pm that night. He looked absolutely exhausted, but he had a small smile on his face. I later found out he passed the exam, but just barely! His score was barely above the minimum passing threshold.When I asked Dapeng what the test was like, he let out a huge sigh and said it was one of the most mentally draining experiences of his life. Having to clearly express complicated scientific notions in technical English writing for hours on end really pushed his language skills to the limit. By the end, his brain felt scrambled like a plate of dry scrambled eggs.But Dapeng gritted his way through that brutal English exam, and he was proud of himself for passing. As difficult as it was, that test helped strengthen his mastery over Environmental Engineering concepts and his ability to communicate those ideas in fluent academic English. It was a true test of endurance!Honestly, I have so much respect for my big bro after witnessing how intensely he prepared and how hard that English exam was. I don't think I could handle anything even close to that level of difficulty right now. Who knows, maybe one day when I'm older I'll pursue Environmental Engineering too. But uh, no promises about passing any crazy exams like what Dapengwent through! For now, I'm sticking to reading comic books and playing video games.篇5My Big Environmental Exam AdventureHi! My name is Lily and I'm 8 years old. I love learning about science, especially anything to do with nature and the environment. That's why I was super excited when my mom told me I got to take a special environmental engineering exam at Beijing University of Technology!On the morning of the exam, I woke up extra early. I had my favorite breakfast of waffles with strawberries and lots of syrup to give me energy for the big test. Then I put on my lucky green t-shirt with a picture of planet Earth on it. I was ready!When we got to the university, I was amazed by how huge the campus was. The buildings were massive and there were students walking everywhere. My mom and I followed the signs to the exam room. I wasn't nervous at all because I had studied really hard.The exam started with some multiple choice questions about things like recycling, pollution, and ecosystems. I flew throughthose no problem! Next up were short answer questions where I had to explain environmental concepts. I wrote all about fossil fuels, the greenhouse effect, and acid rain.Then came the best part - the hands-on experiment section! The professor gave me some materials and instructions. I had to create a simple water filter system to clean a dirty sample of water. I've done tons of experiments at home, so this was right up my alley. I carefully layered the sand, rocks, and carbon between mesh screens in the funnel. When I poured the gross water through my filter, it came out sparkling clean on the other side! Nailed it.The last section tested my environmental engineering skills. I had to look at some building blueprints and come up with ways to make the design more eco-friendly and energy efficient. I suggested adding solar panels to the roof, using recycled materials for construction, and planting a green roof garden. The professor seemed really impressed with my ideas!After what felt like no time at all, the exam was over. I was a little sad because I had so much fun. On the way out, I got to tour some of the cool environmental science labs at the university. The students showed me their green roof research, rain gardenprojects, and renewable energy experiments. It was all so fascinating!My mom took me out for a celebratory ice cream after the exam. As I joyfully devoured my double scoop chocolate sundae, I thought about how I can't wait to study environmental engineering for real someday. I'll get to spend every day learning about ways to help protect our beautiful planet. Exams about saving the Earth? Sign me up!篇6My Fun Summer Exploring NatureHi there! My name is Lily and I'm 8 years old. This summer, I had the best time learning all about the environment and nature. My mom works at the university studying things like pollution and how to protect trees and animals. She took me on some really cool field trips!We started by visiting a forest near our city. My mom called it an "ecosystem" which means all the living and non-living things that make up an area. In the forest, we saw so many tall trees with branches reaching up to the sky. My favorite was the oak tree because it had such pretty leaves. We also spotted lotsof birds making nests and squirrels scampering around gathering food.My mom said the trees, animals, soil, and other parts all depend on each other in the forest ecosystem. The trees provide shelter and food for the critters. And the animals help spread seeds so new trees can grow. The fallen leaves and branches make the soil nutrient-rich so the trees and plants can thrive. It's all one big connected cycle!After the forest, we went to a river ecosystem. It was so peaceful listening to the babbling water flowing over the rocks. We could watch the sun glistening off the surface of the water. My mom helped me try to catch some of the tiny aquatic insects crawling on the rocks. She said they were "macro-invertebrates" and seeing lots of them is a sign of good water quality.We also found some fish swimming around! My mom identified them as trout using a fish guide. I was really excited because I had never seen live trout before. They were pretty colors like green, yellow and red. My mom said trout need cold, clean river water to survive so that's why we could find them there. She also warned me that if too much pollution gets in the river from factories or people littering, it could hurt the trout and other creatures.The next place we explored was a prairie ecosystem full of grasses and wildflowers. The grasses were taller than me and made a swishing sound when the wind blew through them. We saw bright yellow sunflowers, purple coneflowers, and these funny puffy white flower balls my mom called "Queen Anne's Lace." Lots of bees and butterflies were flitting around pollinating the flowers.My favorite prairie creature was the giant fuzzy bumblebee! My mom let me try to catch one gently in a jar so I could look at it up close before letting it go again. I loved watching its tiny wings flapping so fast. We also spotted some deer carefully stepping through the grasses to nibble on the plants. My mom said deer, bees, flowers and grasses all evolved together in the prairie over many years. If one part was missing, the whole ecosystem could fall apart!After a few weeks of nature adventures, I felt like such an expert on ecosystems. My mom was really proud of how much I had learned. She said things like water quality, soil health, biodiversity, and habitat loss are huge issues that environmental engineers work hard to study and improve.Seeing all the different ecosystems made me really appreciate how important it is to protect our forests, rivers,prairies and every other part of nature. All the living things relied on having a clean, balanced place to make their home. I don't want pollution or human activities like deforestation to ruin these special places!So on the last day of summer, I told my mom I had decided to become an environmental engineer when I grow up, just like her. I'll get to spend my career figuring out ways to keep our planet's ecosystems healthy for generations to come. Whether it's developing cool new recycling technology, planting trees in cities, or cleaning up contaminated water, I can't wait to help make our world a better place!I know I'm just a kid, but we all need to do our part to take care of the environment. Maybe you could start by learning what types of ecosystems are near your home. Pay close attention to the trees, plants, insects and animals that live there. Think about how they all connect together in a cycle of life. And don't litter or damage their habitats when you visit! Let's all work to keep our ecosystems in balance.Well, that's my story of my awesome summer in nature. Write to me and let me know what you learned about your local environment. I'll be back next year with more tales of my environmental adventures!。