(天津专版)2018年高考英语二轮复习专题三阅读理解第三节题组训练2科普知识

第三节题组训练 2 科普知识

A

(2017·河东区一模)

Do you ever wish for a little more time to do everything you need to do？Well，on July 1 you’ll be getting it—but only one more second.

On July 1 at exactly 7：59：59 a．m.Beijing time (or on June 30 at 23：59：59 UTC，Coordinated Universal Time)，the world’s atomic(原子的) clocks will pause for a single second，or，more precisely，change to the unusual time of 7：59：60，according to .The addition of a leap second(闰秒)，announced by the Paris Observatory，is to keep our clocks in ti me with the slowing of Earth’s rotation(旋转) and astronomical time as measured by the sun.

Just one extra second could cause big problems and affect the way computers and websites work，however.When the last leap second was added back in 2012，more than a few websites had some trouble.As reported by ，popular sites like the community website Reddit crashed when the leap second was added.

For Reddit，the problem was eventually found to be with a Linux system that got confused when it checked the network time and found an extra second.

Speaking to Wired about the problem back in 2012，Linux creator Linus Torvalds commented：“Almost every time we have a leap second，we find something.It’s really annoying，because it’s code(代码) that is almost never used，and thus not tested by users under their normal conditions.”

Companies have had to think of their own solutions，and Google’s “leap smear” may be the best-known example.As company engineer Christopher Pascoe explains in a blog post，companies usually try to fix the problem by turning back the clocks by

one second at the end of the day so that they play that second again.

However，Pascoe believes this creates problems.He asked：“What happens？Does e-mail that comes in during that second get stored correctly？”

Google has a solution：Cut the extra second into milliseconds and then put these tiny amounts of time into the system throughout the day.“This means that when it became time to add an extra second at midnight，”says Pascoe.“Our clocks have already taken this into accoun t over the course of the day.”

For many companies without Google’s money，however，the leap second will likely still cause some crashes.Don’t worry，though—at least it won’t last long!

1．Why do we need to add a leap second?

A．Th e world’s atomic clocks are set to do so.

B．To keep in time with the world’s computers.

C．To keep atomic clocks in time with the slowing of Earth’s rotation.

D．To record the changes to astronomical time.

答案 C

解析细节理解题。根据文章第二段中“The addition of a leap second(闰秒)，announced by the Paris Observatory，is to keep our clocks in time with the slowing of Earth’s rotation(旋转) and astronomical time as measured by the sun.”可知，闰秒是由于地球自转变慢引起的，为了与由太阳测量的天文时间一致而增加一秒，故选C。

2．What happened to the website Reddit when the leap second was added in 2012? A．It crashed because of a virus attack.

B．Its network time added two extra seconds.

C．All of the code in its Linux system went wrong.

D．One of its software systems got confused and the site broke down.

答案 D

解析细节理解题。根据第三段最后一句和第四段中“th e problem was eventually found to be with a Linux system that got confused when it checked the network time and found an extra second”可知，闰秒发生时，网站崩溃，运行系统混乱，故选D。

3．What does the underlined word “something” refer to in the 5th paragraph? A．The code not working properly.

B．The extra second.

C．The problem.