问题:
It goes on, ________.
A.hour in hour
B.an hour after an hour
C.a hour in a hour
D.hour after hour
It goes on, ________.
A.hour in hour
B.an hour after an hour
C.a hour in a hour
D.hour after hour
A.hour in hour
B.an hour after an hour
C.a hour in a hour
D.hour after hour
参考答案: