He was puzzled by this phenomenon. He be
题型:选择题
问题:
He was puzzled by this phenomenon. He began to try every approach _________ the best way of working it out.
A.known to find
B.knowing to find
C.known finding
D.knowing finding
He was puzzled by this phenomenon. He began to try every approach _________ the best way of working it out.
A.known to find
B.knowing to find
C.known finding
D.knowing finding