=> 1. Nam said that he liked to do physics experiment. ( câu gián tiếp) 2. The foreigners asked Nam if he would leave Viet Nam the following day. 3. David asked John why humans couldn't live on Venus. 4. If there weren't so many billboards in our city at night, we could enjoy the view. ( câu điều kiện loại 2 -> không có thật ở hiện tại) 5. Because his room is untidy, his mother is unhappy. ( because S V : bởi vì)
