—Would you like to play tennis with me it doesn’t rain tomorrow? —Sure I am busy.A. if;

问题补充：

—Would you like to play tennis with me it doesn’t rain tomorrow?

—Sure, I am busy.

A. if; since

B. whether; but

C. if; unless

D. because; until

答案：

A. if; since

B. whether; but

(答案→)C. if; unless

D. because; until

解析：句意：如果明天不下雨，你愿意和我一起打网球吗？当然，除非我忙。If如果，since自从，既然，由于；whether是否；but但是；unless除非；until直到。所以选C。