English is very useful, but it is ____ to learn.
A.
A, different
B.
B, easy
C.
C, hard
D.
D, both A and B
正确答案是D
English is very useful, but it is ____ to learn.
A.
A, different
B.
B, easy
C.
C, hard
D.
D, both A and B
正确答案是D