The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.
A. to be based on B. to base on
C. which to base on D. on which to base
The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.
A. to be based on B. to base on
C. which to base on D. on which to base
D
on which to base his arguments in favor of the new theory = The professor will base his arguments in favor of the new theory on sufficient grounds.