在矿床露天开采的实际生产中通常采用()、()和()等控制爆破手段来避免或减少台阶靠帮或并段爆破对最终边帮的稳定性造成的危害。
参考答案:预裂爆破;缓冲爆破;光面爆破
The new law says that people_______ drive after drinking wine.
A.wouldn't
B.needn't
C.won't
D.mustn't