He has made another wonderful discovery, ______ of great importance to science and man.
A.which I think is B.which I think it is C.of which I think it is D.I think which is正确答案A
He has made another wonderful discovery, ______ of great importance to science and man.
A.which I think is B.which I think it is C.of which I think it is D.I think which is正确答案A