1.
1) Did many people from our country travel around the world 2 years ago?
2) Did many people from our country travel around the world 2 or 3 years ago?
3) Many people from our country travelled around the world 2 years ago, didn't they?
4) When did many people from our country travel around the world?
2.
1) Did my mom read on interesting book last week?
2) Did my mom or dad read on interesting book last week?
3) My mom read on interesting book last week, didn't she?
4) Who read on interesting book last week?