It is usually warm here in March but it be rather cold sometimes.A. mustB. can C. should

问题补充：

It is usually warm here in March, but it be rather cold sometimes.

A. must

B. can

C. should

D. would

答案：

A. must

(答案→)B. can

C. should

D. would

解析：本题考查情态动词。must必然，一定；can可能；should应该；would（过去）将，总会。本题提供的语境是“有时可能会……”。