=>
13. The surgeon put off the operation as/because/since the patient was still too weak. (put off : trì hoãn = postpone)
14. A teenage boy is responsible for six stolen cars from the park. (responsible for : chịu trách nhiệm)
15. I appreciate you giving me a lift. (appreciate sb Ving sth)
16. I don't mind looking after the baby for you. (don't mind Ving : không phiền)
17. Why don't you try to use honey instead of sugar? (why don't you V)
18. Don't waste time copying your work out again. (waste time Ving : lãng phí thời gian làm gì)
19. Don't put off going to the dentist's.
20. He apologized for not saying/not having said goodbye to her at the airport.