The professor could hardly find necessary grounds_______his arguments in favour of the new theory.

A. to be based on　　　　　　　　　　　　　　　 B. to base on

C. which to base on　　　　　　　　　　　　　　 D. on which to base

A.　　  be based on　　　　　　   　　　　　　  

B.　　  base on

C.　　  be basing on　　　　　　   　　　　　　  

D.　　 base by

Without facts，we can’t form a correct opinion，for we need to have actual knowledge______our thinking.

A.which to be based on　　　　　　　　　 B.which to base on

C.on which to base　　　　　　　　　　　 D.which to base

Without fact, we can’t form a correct opinion, for we need to have actual knowledge __________ our thinking.

A. which to be based on　　　 　

B. which to base on

C. on which to base　

D. which to base

--Do you think it true that all the theories should ________ facts?

--I don’t suppose so. If so, there would be no predictions(预言)

　 A. be made on　 　B. be based on　 　　　C. be set up with　 　　D. be built with