_____ three influenza type A virus subtypes(子类型) have been found in pigs.
#25069
A
By far
B
As far as
C
So far
D
Till far
推荐题目
Please don’t run _____ far. 
#25059
A
much
B
more
C
that
D
fairly
The soup was cold, but it was ______ an excellent meal.
#22921
A
yet
B
already
C
otherwise
D
therefore