—Have you cleaned the room yet？
—Yes，I _______it an hour ago.
A.clean B.has cleand C.cleaned
Which of the following signs means “Throw litter here.”？
A. 
B. 
C. 
— When did you close friend go________?
—At the age of forty,after a fever,he couldn’t hear anything..
A.blind B.deaf C.mad
—We should learn to avoid______the same mistake in each exam.
— I agree with you compeletaly.
A.to make B.making C.made
____your support,they succeeded in finishing the hard work at last.
A.Thanks to B.After all. C.So far.
______of the earth is covered with water.
A. three fourth
B.threes fourths
C.three fourths
