1.
1)were
2)discovered
3)found
4)visited
5)arrested
6)went
2.
a) Why did you take my pen?
b) Did he eat all the cakes?
c) What did the teacher find in the cupboard?
3.
1) was your father taking
2)Were the thieves wearing
3)were I travelling
4.
1) Alice was reading comics while her mom was cooking the evening meal.
2)Mark was working on the computer when he heard a noise.
3)While I was walking home from school, it started to rain.
5.
1) Was it raining yesterday at 6 p.m.?
2)They didn't work in the park last week.
3) While he was visiting New York, he met new friends.