( )1.We have learned _____ the rocks on the moon are 3,500 million years of age.
D.that
( )2.Do you know _______ our motherland sent the first satellite into space?
C.when
( )3.________ exercise book has not been found is still unknown.
D.That
( )4.Do you know ________ first stepped on the moon?
B.who
( )5.It is known to us ________ discovered the mystery of rainbow.
C.who
( )6.Can you tell me ________ room she lives in?
D.which
( )7.I want to use the same dictionary ______was used yesterday.
A.which
( ) 8.He isn't such a man ______he used to be.
D.as
( ) 9.The reason ______he didn't come was ______he was ill.
A.why; that
( ) 10.You can depend on whatever promise _______ he makes.
A./
( ) 11.The clever boy made a hole in the wall,______ he could see _____ was going on inside house.
B.through which; what
( )12._____ today,he would get there by Friday.
C.Were he to leave
( )13.Should it rain,the crops _____ .
A.would be saved
( )14.You _____ come earlier.The bus left a moment ago.
B.should have
( ) 15.He treated me as though/as if _____ his own son.
D.I were
( )16.I _____ you some money,but I hadn’t any on me then.
B.would have lent
( )17.A few minutes earlier and we _____ the rain.
C.could have caught
( ) 18.--- “Have you ever been to Beijing?”
--- “No,but I wish I _____”
D.had
( )19.--- “What will you do during the summer holiday?”
--- “I don’t know,but it’s high time _____ something.”
B.I’ll decide
( ) 20.What should we do if it _____ tomorrow?
B.would snow