The scientists are beating their brains,
问题:
The scientists are beating their brains, trying to ______ a solution to the problem.
A.look up to
B.live up to
C.come up with
D.keep up with
The scientists are beating their brains, trying to ______ a solution to the problem.
A.look up to
B.live up to
C.come up with
D.keep up with