--Who______ it be that is knocking at the door?
--It ______ be Father, but I’m not sure.
A. can; may B. can; must
C. must; can D. may; must
Judging from his______ expression, this problem must be quite ______.
A. puzzling; puzzling B. puzzled; puzzled
C. puzzling; puzzled D. puzzled; puzzling
Listen! Do you hear someone _____ for help?
A. calling B. call C. to call D. called
--How is your cousin, Kate?
--She broke her leg and ______ medical treatment since.
A. is receiving B. has received
C. received D. has been receiving
--Mom, may I play computer games just for a while?
--______! Dad is writing his paper.
A. Help yourself
B. It's up to you
C. Go ahead
D. Behave yourself
It took ______ building supplies to construct these energy saving houses. It took brains, too.
A. other than B. more than
C. rather than D. less than
