关于过去进行时和一般过去时,用括号中动词的适当形式填空
1.As my father ____(leave)the house ,the postman ____(arrive).
2.Tom ____(work)in the garden while I ____(sit) in the sun.
3.As I _____(walk) down the street ,I _____(meet) Charlie.
4.While he ____(read) the letter ,he_____(hear) a knock at the door.
5.While mother ______(prepare) lunch ,Janet_____(set) the table.
6.She ______(drop) the tray when I _____(speak) to her.