问题 多项选择题 案例分析题

某建筑物采用TN-C-S系统供电,建筑物地下室设有与大地绝缘的防水层。PEN线进户后即分为PE线和N线,并打人工接地极将PE线重复接地,变电所系统接地RA和建筑物重复接地RB的阻值分别为4Ω和10Ω。各段线路的阻值如图1所示,为简化计算可忽略工频条件下的回路导体电抗,请回答下列问题:

在上题(见图3)的条件下,当设备A发生接地故障时,下列哪种措施无法防止在设备B处发生电击事故?()

A.在设备B的配电线路上装用RCD

B.另引其他专用电源给设备B供电(设备A和设备B之间无PE线连接)

C.给设备B另作接地以局部TT系统供电

D.给设备B隔离变压器供电,不接PE线

答案

参考答案:A, C

阅读理解

阅读理解。

     Adrian's "Amazing Race" started early when his parents realized that he, as a baby, couldn't hear a thing,

not even loud noises. In a special school for the hearing-impaired (听觉受损的), he learned sign language and

got to mix with other disabled children. However, the sight of all the disabled children communicating with one

another upset his mother. She wanted him to lead a normal life. So after speaking to an advisor, she sent him to

private classes where he learned to read lips and pronounce words.

     Later on, Adrian's parents decided to send him to a regular school. But the headmaster tried to prevent them

from doing so, saying regular school couldn't take care of a special needs students. His parents were determined

to take the risk and push him hard to go through his work everyday because they wanted to prove that, given

the opportunity, he could do anything. Adrian made the grade and got accepted. It was a big challenge. The pace

(节奏) was faster so he had to sit at the front of the class and really pay attention to the teacher, which wasn't

always easy. But he stuck to it and did a lot of extra work after school.

     The efforts made by Adrian and his parents paid off. Adrian graduated with good grades and got into a top

high school. He also achieved a lot in life outside school. He developed a love for the outdoors and went to Nepal

to climb mountains. He even entered the World Yacht Race 05/06-being the first hearing-impaired Asian to do so.

     But none of these achievements would have been possible without one of the most important lessons from

his mother." "If you believe in yourself and work hard, you can achieve great results." She often said.

1. How did Adrian communicate with other children in the special school?

A. By speaking.

B. By using sign language

C. By reading lips

D. By making loud noises

2. Adrian's parents decided to send him to a regular school because _____.

A. they wanted him to live a normal life

B. they wanted to prove the headmaster wrong

C. he wouldn't mix with other disabled children

D. he wasn't taken good care of in the special school

3. How did Adrian finally succeed in his study?

A. He did a lot of outdoor activities.

B. He was pushed hard to study every day.

C. He attended private classes after school.

D. He worked very hard both in and after class

4. Why is Adrian's life described as an "Amazing Race"?

A. He did very well in his study

B. He succeeded in entering a regular school

C. He reached his goals in spite of his disability

D. He took part in the World Yacht Race 05/06

问答题 简答题