We know that about seventy percent _____ the earth _____ covered by water.
A. /; is B. of; are
C. of; is D. about; are
you drive, you will be.
A. More carefully; safer; B. The more careful, the safer
C. The more carefully, the safer. D. The more careful, the safer
The policeman asked the child ________ cross the street ________ the traffic lights turned green.
A. not, when B. not to, until
C. didn't, before D. not to, after
— I have great _______in finishing the work by myself. Could you help me?
— No problem.
A. fun B. success
C. advice D. difficulty
-How well she sings!
-Yes, she has a very sweet __________.
A. voice B. Sound
C. Noise D. shout
He found very difficult the math problem.
A.that；to solveB.this；solving
C.it；to solve D.it；solving
