—Did you mend the radio yourself?
—No，I____. Because I don't know how to do it.
A. mended it B. get mended it
C. got it mended D. will mend it
The math problem is so hard that ________ students can work it out.
A. a few B. a little C. many D. few
. The train _____ for twenty minutes.
A. left B .has left C. is leaving D. has been away
We can't do it ______ your help.
A. with B. of
C. under D. without
The population of the world in 20 century became very much _____than that in 19 century.
A. bigger B. lager
C. greater D. more
We will have a _________ holiday after the exam．
A. two month B. two month’s
C. two-month． D. two-months
