问题
选择题
----May I go swimming this afternoon?
----I'm afraid not _______ you have finished your homework.
A．unless
B．because
C．if
D．though
答案
答案：A
题目分析: 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