If you miss this chance, it may be years ____ you get another one.
A. as B. before
C. since D. after
_____the damage is done, it will take many years for the farmland to recover.
A. Until B. Unless
C. Once D. Although
He is a shy man,___he is not afraid of anything or anyone.
A. so B. but
C. or D. as
_______online shopping has changed our life , not all of its effects have been positive.
A. Since B. After
C. While D. Unless
The children, ______ had played the whole day long, were worn out.
A. all of what B. all of which
C. all of them D. all of whom
We have launched another man－made satellite，________ is announced in today's newspaper.
A. that B. which
C．who D．what
