问题

Tell John not to leave the house________he makes sure that all the lights are turned off.[ ]

A: unless
B: if
C: once
D: because

正确答案是：

同类题型

Are you free after school? —SorryI’ve planned to treat a friend of mine to dinner ________for his help

Why! Where’s my mobile phone Maybe I leftit on the plane—My goodness! Youthingsbehind

My favourite subject is English. But I don’t like Math. —I like English ___________ and I don’t like Math ___________.

according to the instructions，the medicine will work for your headache．

It is reported that two schools, __________ are being built in my hometown, will open next year.