车钩各部焊修之前（）预热。
A.必须
B.应该
C.不应
参考答案：A
Remember never to ask a European and an American personal questions. It is almost certain
that they ______ for it . [ ]
A. are not prepared
B. don't prepare
C. haven't prepared
D. are not preparing
—You are never late for school, are you?
—________.
A. Yes, sometimes
B. No, some times
C. Yes, never
D. Sure, I'm not.
