爆破后，由于某种原因造成的部分或单个雷管不起爆的现象即为拒爆。（）
参考答案：对
Hardly ________________ she heard the strange scream coming from behind a tree.
A．had she walked out of the woods than
B．did she walk out of the woods when
C．had she walked out of the woods when
D．she had walked out of the woods when
防碰天车装置必须（）检查一次，更换防碰天车绳后应进行调整。
A、两天
B、三天
C、每天
D、每班
