单项选择：1.They didn't start to work _____the boss arrived.A.so B.as soon as C.while D.until

单项选择：1.They didn't start to work _____the boss arrived.A.so B.as soon as C.while D.until
2.We must set off now ,______ we'll miss the last train.
A.and B.while C.then D.or
3.Can you name three countries _________ Chinese is used as one of their languages?
A.that B.which C.where D.there
4.There is no air ________ water on the moon.
A.and B.or C.yet D.so
5._______ she finishes reading the book ,she will give it to you.
A.When B.While C.Before D.Until
6.The lights went out _______ thev were reading.
A.while B.before C.after D.if
7.Have you been here________?
A.at eight the day before yesterday
B.since one year ago
C.two years ago
D.since two years
8.Every night Li Lei studied hard and did his homework _____ 11:30 pro.
A.at B.since C.until D.for