3: on
4: on
5: at
6: in
7: on
8: at
9: in
10: at
11: on
12: on
Answers:
3. on
4. on
5. at
6. in
8. at
9. in
10. in
11. on
12. at
If you read each sentence filling the blanks with each one, they all clearly make sense. Hope this helped :) Have a good day!
