-----Alice, you clean the blackboard today, _________?
----- But I cleaned it yesterday.
A. won’t you B. will you C. didn’t you D. don’t you
--- Why is the cake so expensive?
---- Maybe you don’t know a cake made of wheat costs less than _____ made of rice.
A. one B. that C. the one D. another
I _____ sooner but I didn’t know that they were waiting for me .
A. had come B. was coming C. would come D. would have come
Experiments of this kind ___in both the U．S and Europe well before the Second World War．
A．had conducted B． have conducted
C．have been conducted D. had been conducted
The situation forced my mother and I exchanged our roles as child and caretaker, making me grow up much faster than the _____ child.
A. average B. ordinary C. common D. usual
It is the first time that he ______ here and now it is high time that he ______ around.
A. come; should be shown B. has come; was shown
C. came; was shown D. has come; be shown
