——Helen do you know if Martin to my party next week?——I think he will come if he free.A

问题补充：

——Helen, do you know if Martin to my party next week?

——I think he will come if he free.

A. will come; will be

B. will come; is

C. come; is

D. comes; will be

答案：

A. will come; will be

(答案→)B. will come; is

C. come; is

D. comes; will be

解析：句意：海伦，你知道马丁下周是否来参加我的聚会吗？——如果他有空，我想他回来的。结合语境可知上文是宾语从句，描述的是将来发生的动作，故用一般将来时态。下文是条件状语从句，当主句描述将来动作时，从句中用一般现在时态表示将来的动作。故选B。