Question

【题目】The doctor looks tired and sleepy _______ he stayed up late to look after his patients yesterday.

A.becauseB.ifC.unlessD.until

Answer 1

【答案】A

【解析】

句意：这个医生因为昨天熬夜照顾病人，所以看起来又累又困。

考查连词用法。because因为；if如果；unless除非，如果不；until直到。根据句意，这个医生看起来又累又困是因为昨天熬夜照顾病人，表示因为，原因。故选A。