1. Hoa asked me if => whether I could have a picnic with her in the country or not.

2. Most of monkeys both in the forest and in the zoo are interested in bananas. ( Câu này không có lỗi sai nên không cần sửa)

3. Air pollution, together with littering, are=> is causing many problems in our large, industrial cities

today.

4. These televisions are quite popular in Europe, but those ones => those are not

5. Not only Ha but also her friends was=> were present at my fifteenth birthday party.