You must keep on working in the evening. you are sure you can finish the task in
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You must keep on working in the evening， you are sure you can finish the task in time.?
A.as B.if C.when D.unless
试题答案
D
unless引导一个状语从句，意思同if...not...如误选C，是因为没有正确理解句子的意思。句意为：你必须在晚上继续工作，除非你确信会按时完成任务。