Question

--Would you like to go bike riding with us tomorrow?  ---Sure, ____ I am busy.

A．since

B．unless

C．when

D．until

Answer 1

B

连词辨析。since 自从……以来；unless除非；when 当……时；until直到……。句意：明天你愿意和我们一起骑自行车兜风去吗?——当然了，除非我忙。故选B。