помогите пожалуйста.Insert the prepositions.1 My father works ____ an international

помогите пожалуйста.
Insert the prepositions.
1 My father works ____ an international company.
2 He's got a degree ___ BA.
3 What university does she study ____?
4. She is responsible ___ production.
5 Next summer I want to work __ a salesman.