1 - has to

2-  have to

3 - have to

4 have to

5 has to

6 have to

7 have to

2.Do students from different countries have to live in America?

3.Do exchange students have to speak english better?

4.Do exchange students have to get scholarship?

5.Does an exchange student has to know english well?

6.Do we all have to respect teachers and students?

7.Do they have to learn different customs and traditions?