You look so tired. Why not __________?
A. stop to work B. to stop to work
C. stop working D. to stop working
Many kinds of plants and animals are extinct (灭绝). The same thing ________ around the world.
A. happen B. happened C. is happening D. happens
Be careful ________ the street when you are alone.
A. to cross B. with cross
C. crossing D. of crossing
______ June 9th, he helped a man ________ a fire.
A. In; into B. On; out of C. In; out of D. On; into
There was something wrong with the line. We couldn’t _______ each other clearly.
A. listen B. sound C. hear D. speak
The room is ________ to hold 100 people.
A. enough big B. too big C. big enough D. big too
