问题 填空题

如图所示,检查视力时,人与视力表之间的距离应为5m。现因屋子太小而使用了一个平面镜,视力表到平面镜的距离为3m,那么人到镜子的距离应为         m。

答案

2

题目分析:视力表距离平面镜3m,根据平面镜成像特点,视力表的像到平面镜的距离是3m,视力表和视力表的像之间的距离是6m,检查视力时眼睛离视力表的像距离是5m,所以人到平面镜的距离为2m.

点评:平面镜有两个重要的应用:一是改变光的传播路线;二是成像.检查视力是利用平面镜成像特点,来增大视觉空间.

多项选择题
阅读理解

阅读表达。

     [1]Sending text messages from your mobile phone while driving is more dangerous than driving after

drinking, which is found by the Transport Research Laboratory (TRL).

      [2]The reaction time of people who sent text messages as they drove slowed by 35%, while the reaction

time of those who had drunk alcohol slowed by 12%."This research shows how dangerous it is to text while

driving," researcher Nick Reed said in a statement. He said drivers who texted were distracted by trying to read

small texts on the phone and by thinking about how to write their messages. And using the phone requires them

to put their hands off the wheel. The combination of factors caused the slowness of reaction and the impairment (减弱) of vehicle control.

     [3]One conclusion researchers made about why texting while driving is so dangerous is the length of time it

takes to write a message. The TRL said that writing a text message behind the wheel took 63 seconds, in which a car travels nearly a mile within town centre speed limits and over a mile within motorway speed limits.

     [4]Nearly half of the 18-to 24-year-olds admitted texting as they drove, another survey discovered.

     [5]The TRL study selected 17 people from the 18-to 24-year-old age group to take part in a simulated (模拟的) road test, in which they were on a variety of roads."The participants in this study were almost unanimous (一致同意的) in their view that texting while driving was the most dangerous action on the road," RAC Director Stephen Glaister said.

      [6] "We need to ensure that drivers who love texting understand that texting is one of the most dangerous

things that can be done while in charge of a car," Glaister said in a statement.

1. What's the main idea of the passage? (no more than 10 words)

____________________________________________________________________________________

2. Give two factors which caused the slowness of reaction of a driver while texting. (no more than 20 words) ① . ________________________________________________________________________________

② . ________________________________________________________________________________

3. Complete the following statement with proper words. (no more than 4 words)

    The researchers inferred it's the time a driver spends reading and writing a message that ___________

______________________________________________________________________________________.

4. What does the underlined word "which" in Paragraph 3 probably refer to? (no more than 2 words)

_____________________________________________________________________________________

5. Fill in the blank in Paragraph 5 with proper words. (no more than 8 words)

_____________________________________________________________________________________