4) He asked me what I (want) to eat that night.
want -> wanted
câu tường thuật ở dạng câu hỏi Wh-question:Wh+S+V(lùi thì)
tonight:tối nay(thì HTĐ)->that night(QKĐ) nên chuyển want thành wanted
He (work) as a research and development chemist for 10 years, then he retired.
had worked
His doctor advised him (not / take) any strenuous exercise.
-> Not to take
S+advise+sb+to+sthing=S+advise+on+sthing(đưa ra lời khuyên)