----May I go swimming this afternoon?--Im afraid not you have finished your homework.

问题补充：

----May I go swimming this afternoon?

----Im afraid not you have finished your homework.

A. unless

B. because

C. if

D. though

答案：

(答案→)A. unless

B. because

C. if

D. though

解析：

试题分析: 句意：今天下午我可以去游泳吗？我恐怕不能，除非你已经完成了作业。unless除非，because因为，if 如果，though尽管。根据语境可知选A