Question

【题目】You can go out, ______ you promise to be back before 10 o’clock.

A. unless B. as long as C. because D. since

Answer 1

【答案】B

【解析】

试题分析：句意：只要你答应10点前回来，你就可以外出。Unless除非，如果…不…；as long as只要；根据句意可知B正确。