His appearance has changed so much that you _____ not recognize him.

A．must

B．need

C．may

D．ought

断层对爆破后边坡稳定性的影响取决于以下哪些因素？（）

A.断层的产状与预留边坡的走向及边坡坡度的关系

B.断层的中岩石的颜色

C.断层带的宽度、破碎程度、胶结程度

D.断层与药包位置的关系