来自孙兴东的问题
一道选择题：Iwont'tbeabletoattendthemeeting____I'llbeonholidaywithmyfamily.A:ifB:sinceC:thoughD:while答案是B,我想知道为什么
一道选择题：Iwont'tbeabletoattendthemeeting____I'llbeonholidaywithmyfamily.
A:ifB:sinceC:thoughD:while
答案是B,我想知道为什么
