What【were 】you 【doing 】when I called you?
用过去进行时,意思是：我打电话的时候你正在干什么?
Yesterday I 【fell 】and【hurt】my leg.yesterday 是过去的时间,所以动词用过去式,hurt 的过去式还是 hurt.We weren't happy with the hotel.Our room 【was 】small and it【wasn't 】clean

祝你开心.