Question

【题目】You can't be successful _______ you keep working hard.

A. if B. unless C. because D. when

Answer 1

【答案】B

【解析】句意：除非你继续努力，否则你不可能成功。A. if“如果”；B. unless“除非”；C. because“因为”；D. when“当……的时候”。故选B。