在有火灾爆炸危险场所需在压力容器内部作业，应采取（）照明。
A.普通电灯
B.防爆电气
C.惰性气体充装的电灯
参考答案：B
When asked why he went there, he said he was sent there __________ for a space flight.
A．training
B．being trained
C．to have trained
D．to be trained
尾矿坝坝体有软弱夹层或抗剪强度较低且背水坡较陡而造成的滑坡，首先应( )。
A．放缓坝坡 B．降低库水位C．在坝脚排水压重 D．固脚防滑
