帮我做几道选择题1.He made another wonderful discovery,______ of grea

帮我做几道选择题
1.He made another wonderful discovery,______ of great importance to science.
A.which I yhink is B.which I think it is C.which I think it
2.South of the lake ____ two famous universities.
A.have B.has C.are D.is
3.He has never done it before;I`m not sure whether he`ll _____ the other employers.
A.adjust B.fit in with C.keep it up D.get along
4.The house is becoming two expensive for them to _______.
A.take up B.go up C.keep up D.put up
有空的话帮我解释下为什么选这个答案,