Great as Charles Darwin was, his theory of evolution（ ）and is being modified by the work of scientist of our time.
A.正确答案Cmay be challenged
B.is to challenge
C.has been challenged
D.is challenging
Great as Charles Darwin was, his theory of evolution（ ）and is being modified by the work of scientist of our time.
Great as Charles Darwin was, his theory of evolution（ ）and is being modified by the work of scientist of our time.
A.正确答案Cmay be challenged
B.is to challenge
C.has been challenged
D.is challenging
