Question

【题目】—I'm leaving for the doctor's this afternoon.

—OK, but make sure __________ when you leave.

A. to lock up

B. for locking up

C. you lock up

D. you locked up

Answer 1

【答案】C

【解析】句意:——我今天下午要去看医生。——好，但当你走的时候一定要锁好门窗。make sure后面的宾语从句常使用一般现在时态。