---How long are you staying?-I don’t know. .A. That’s OK.B. Never mindC. It dependsD. I

问题补充：

---How long are you staying?

---I don’t know. .

A. That’s OK.

B. Never mind

C. It depends

D. It doesn’t matter

答案：

A. That’s OK.

B. Never mind

(答案→)C. It depends

D. It doesn’t matter

解析：考查情景交际。That’s OK.不客气；Never mind不介意；It depends视情况而定；It doesn’t matter没关系。句意：你要呆多长时间？我不知道。视情况而定。所以选C。