限时电流速断保护的动作时限为（）
A.瞬时动作
B.短延时动作
C.长延时动作
参考答案：B
Make sentences. 连词成句，注意标点符号。
1. is what it doing
2. at the look tiger
3. jumping the is rabbit
4. is elephant doing what the
5. pandas climbing are
6. they what doing are
按照干扰频谱的不同，无线电通信干扰可分为（）。
A.瞄准式干扰
B.半瞄准式干扰
C.阻塞式干扰
D.压制性干扰
