超星 - 状语从句练习1 - 查题吧

单选题

I hadn't been reading for half an hour _____ I heard steps outside.

A. once
B. as soon as
C. while
D. when

单选题

_____ you seem to know them, why don't you introduce me to them?

A. Since
Because
C. When
D. For

单选题

We'll let you use the room _____ you keep it clean and tidy.

A. when
B. where
C. while
D. on condition that

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