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

考查時(shí)間狀語(yǔ)從句。句意“昨晚我爸爸正在為演講做準(zhǔn)備，而媽媽正在洗衣服。”while表對(duì)比，前后都用進(jìn)行時(shí)。故選B。