问题 单项选择题

玻璃破碎探测器是指()。

A.用于围墙、栅栏等周界报警,可用于规则或不规则的周界环境

B.用摄像机作为探测器,通过检测视频信号亮度等级的变化来触发报警

C.利用压电式微音器,装于面对玻璃之位置。由于只对10~15kHz高频的玻璃破碎声音进行有效的检测,不会因玻璃本身的振动而引起反应

D.一般由开关传感器(如微动开关、磁簧开关、干簧继电器、门磁开关等)与相关电路组成常开或常闭式报警装置

答案

参考答案:C

单项选择题
阅读理解

阅读理解。

        Some people have the feeling that nothing can be done about their poor reading ability (能力). They

feel hopless about it. Can you learn to read better, or must you agree that nothing can be done about it?  

         To be sure, people are different. You cannot expect to do everything as well as certain other people

do. If all the students in a class tried out for basketball, some would be very good players; others would be

very poor; and many would be in between. But even the very poor players can become much better player

s if they are guided in the right way, and with plenty of practice. It is the same with reading. Some seem to

enjoy reading and to read well without any special help. Others find reading a slow and tiring job. In

between, there are all degrees of reading ability.    

        Many experiments have shown that just about every poor reader can improve his reading ability. In

these experiments, the poor readers were given tests of reading ability. After some of the causes of their

poor reading were discovered, they were given special instructiong and practice in reding. After a few

months, another test of the same kind was given. In nearly all cases, these people had raised their reading

scores.

1. With the example of basketball players, the author shows . 

 A. why certain people are poor readers.  

B. that there are differences in people’s abilities  

C. why some people are good basketball players  

D. that good basketball players can be good readers

2. To improve their reading albility, people should .  

A. work long and hard            

B. take different forms of tests  

C. have special help and practice    

D. try different reading materials

3. The experiments mentioned in the text show that .  

A. good readers seem to enjoy reading  

B. almost all poor reders can make progress  

C. causes of poor reading are difficult to find out  

D. tests help people improve their reading ability