1 在7点到8点（或任何两个时间点）之间不管做什么，都是在持续进行中的状态，所以用进行时；2 因为是昨天，所以用 ”过去完成时“ I was watching tv while doing my homework (at the same time) between 7(am/pm) and 8(am/pm) last night.
