用括号单词适当形式填空

1.-what were you doing when the alarm clock went off?[do]
-i was playing [play]the piano

2.when it started [start]to rain yesterday,i was reading [read]a detective story

3.while joyce is/was having [have]a medical examination,sandy is/was operating[operate]on a patient's leg

4.I was teaching [teach] some medical students from 6 to 7o'clock yesterday evening

5.when the fire broke out,sammy rescued [rescue]a child from drowning

1. were, doing
was playing
2. started, was reading
3.was having, was operating
4. was teaching
5. was rescuing

1, 用过去进行时，were, doing, was playing
2, started, was reading
3, was having, was operating
4, was teaching
5, was rescueing
表示另一件事情发生的时候，****正在做什么