Question

My father was preparing for his speech __   my mother was doing some washing last night.

     A. if                 B. while               C. unless             D. until

Answer 1

B

【解析】选B。连接两个同时发生的动作，要用连词while。句意：昨晚，当我爸爸准备演讲时，我的妈妈正在洗衣服。