Hehasmadeadiscovery()ofgreatimportancetotheprogressofscienceandtechnology.
A.which I think it is B.which I think is C.I think which is D.of which I think it is正确答案B
Hehasmadeadiscovery()ofgreatimportancetotheprogressofscienceandtechnology.
A.which I think it is B.which I think is C.I think which is D.of which I think it is正确答案B