冲击地压矿井每年至少进行一次（），提高矿井应急救援能力，防范灾害发生和事故扩大。
参考答案：防冲演习
If the weather had been better, we could have had a picnic. But it ______ all day. [ ]
A. rained
B. rains
C. has rained
D. is raining
下列不属于公务员法定培训类型的是( )
A．初任培训 B．转任培训C．任职培训 D．专门业务培训
