在野外常见到的边坡变形破坏主要有（）等几种类型
A.松弛张裂
B.管涌破坏
C.蠕动变形
D.崩塌
E.滑坡
参考答案：A, C, D, E
Bats are surprisingly long-lived creatures, some _______ a life span of around 20 years.
A．had
B．having
C．have
D．to have
You_______ play with the knife. You ______ hurt yourself.
A．mustn’t; may
B．mustn’t; must
C．shouldn’t; must
D．can’t; should
