were you doing是什么時態

　　例句：

　　1.We were watching TV from seven to nine last night. 昨天晚上七點到九點的時候我們在看電視。

　　2.What was he researching all day last Sunday? 上周日他一整天都在研究什么？

　　3.My brother fell while he was riding his bicycle and hurt himself. 我哥哥騎自行車的時候從車上摔下來，受傷了。

　　4.It was raining when they left the station. 他們離開車站的時候天正在下雨。

　　5.When I got to the top of the mountain, the sun was shining. 當我到達山頂的時候，陽光燦爛。