_____ three influenza type A virus subty
题型:选择题
问题:
_____ three influenza type A virus subtypes(子类型) have been found in pigs.
A.By far
B.As far as
C.So far
D.Till far
_____ three influenza type A virus subtypes(子类型) have been found in pigs.
A.By far
B.As far as
C.So far
D.Till far