If cloned animals could be used as organ donors, ().
A、people don’t have to worry about cloning twins for transplants
B、raising animals such as pigs can help solve the problem
C、the human body attacks and destroys tissue from other species
D、it may be more efficient to produce such animals by cloning than by cur
第1题:
Must I stay at the office this afternoon? ---No, you ______.
A、don’t
B、needn’t
C、don’t need
D、can’t
第2题:
A.don’t … at
B.didn’t … at
C.didn’t … in
D.don’t ...in
第3题:
第4题:
We needn't__________. Everything turned _________all right in the end.
A: worry ... up
B: worry ... down
C: have worried ... out
D: have worried ... on
第5题:
-- Ann is in hospital.
-- Oh, really? I __ know. I __ go and visit her.
A. didn’t; am going to B. don’t; would
C. don’t; will D. didn't; will
第6题: