EX2:

1.(-) They didn't decide to leave soon

(?) Did they decide to leave soon?

2.(-)They weren't many homeless people here ten years ago

(?) Were many homeless people here ten years ago?

3.(-) Tom's grandfather didn't use to be a soldier

(?) Did Tom's grandfather use to be a soldier?

4.(-) My teacher didn't started teaching here 6 years ago

(?) Dia my teacher started teaching here 6 years ago?

5.(-) Jane didn't often went to school on foot 3 years ago

(?)Did Jane often went to school on foot 3 years ago?

EX3:

1.took

2.arrived, weren't 

3.said, bought

4.didn't teach

5.started, was

6.Did many rich people donate

7.rang, invited

8.did you watch