Question

【题目】—I’m busy with my schoolwork these days.

—That’s great! You won’t get good grades _________________ you work hard.

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

Answer 1

【答案】C

【解析】本题用逻辑推理法解题。分析主句和从句的关系可知从句是条件状语从句，unless 除非，相当于if not，故选C。