Question

【题目】You have already tried your best， so you _________ worry about the matter.
A.can't
B.needn't
C.mustn't
D.couldn't

Answer 1

【答案】B
【解析】句意：你已经尽最大努力了，所以你不必担心。A. can't 不可能；B. needn't 不需要；C. mustn't 不准；D. couldn't不可能。所以选B。