1.昨天我打给你的时候你在做什么?—我在拉小提琴.

1.昨天我打给你的时候你在做什么?—我在拉小提琴.
what were you doing when i called you yesterday?i was playing the violin.
2.昨天晚上七点半我正在听收音机.
i was listening the radio at 7 last night.
3.昨天早上9点到11点他们正在参观博物馆.
they were visiting the museum from 9 to 11 yesterday morning.
4.昨天傍晚当我到家时,我妈妈正在大扫除.
my mom was cleaning the house when i reached home last night.