接触器由（）、辅助触点及基座等几部分组成。
A.电磁机构
B.触点系统
C.灭弧系统
D.释放弹簧机构
参考答案：A, B, C, D
Read, choose and fill in the blanks. （用is，am，are，was或were填空）
1. I a girl. My name Mary. Those my two brothers.
2. —Where Tina and Kate? —They in the classroom.
3. Where you yesterday?
4. —Hello. Mr Smith at home? —No, he isn't.
5. I wanted to be a policeman when I a boy.
6. —How old you? —I thirteen years old.
严格执行责任制是将社会治安综合治理各项措施落到实处的（）保证。
A.根本
B.重要
C.基本
