----How long are you staying?
----I don't know. .
A. That's OK
B. Never mind
C. It depends
D. It doesn't matter
网友回答
A. That's OK
B. Never mind
(答案→)C. It depends
D. It doesn't matter
解析：本题考交际用语和惯用法。全句合理意思应是：问句：你打算呆多久？答句：我也不知道，视情况而定吧！It（just）depends．是口语，意即“看看再说，视情况而定”的意思，正合语意。That's OK.用于对道谢和道歉的答复（没关系，别客气），Never mind和it doesn't matter用于对道歉的答复，意为“不要紧，没关系”，均不合语境。