（）是反应电压下降到某一整定值及以下动断接点由断开状态到闭合状态的继电器。
A、过电压继电器
B、低电压继电器
C、时间继电器
D、中间继电器
参考答案：B
单词拼写。
1. Anything not made of natural materials is a______.
2. English and Maori are the two o____ languages in New Zealand.
3. On the way to Guilin, we stopped again and again to enjoy the beautiful s_____.
4. The water in the river is s_____. You can walk across it.
5. It was e_____ cold yesterday. I nearly couldn't stand it.
6. Who is the a_____ that designs this skyscraper?
7. She ran away and soon ____(消失) in the rain.
8. Without _____(许可), you can not enter the laboratory.
9. Every child is _____(独特的,唯一的) to their parents.
10. We have made all the ____(安排) for the meeting.
