Question

【题目】He seldom stays up late at night, _______ he has too much work to do.

A. if B. unless C. until D. while

Answer 1

【答案】B

【解析】句意：他很少熬夜，除非有很多工作要做。A. if如果、是否；B. unless除非；C. until直到；D. while而、当……时候。根据前后语句的关系可知，故选B。