Great attention must be paid ________ education，especially in the countryside．
A．develop B．to develop C．to developing D．developing
—Was it in April, 1970 that China ________ sending its first satellite into space?
—Yes, that's right.
A．succeeded in B．managed to C．attempted in D．tried to
As you know，it is my duty to________my younger sisters from being hurt when they are in danger.
A．prevent B．save C．stop D．protect
If no measures are taken, the special wild plant will ________ some day.
A．die out B．die away C．die down 
D．die off
Sir, you ________ take this seat. It’s just for the old.
A. won’t B. can’t C. oughtn’t to D. needn’t
He spoke as though he________ anything of the world.
--Really?
A. knew B. had known C. knows D. has know
