Bài 1: sửa lỗi sai 1. Mary and her children are sitting around the table 2. A large number of Vietnamese student know English 3.It is very difficult for us to preventing forest fires during the drought 4.Would you mind give me a hand, I have a lot of things to do ? 5. The little boy is very intersted in football, but he is actually not good for playing 6. Paula has given up to smoke for 5 months 7. He used to working hard when he was young, but he is old now 8. Peter is used to doing morning exercise every day , didn't he ? 9. This morning I met Mary ,that I hadn't seen for ages 10. They have done the homework since 2 hours 11. How long does your mother go to market? 12. Marie Curie's dream was to beacome a scientific 13. They were hungry, so they suggested to have dinner early 14, They agreed with wating for me if I was late 15, I hate the way you never look at me whenever you speak to me 16, The purpose of volunteer work is to help poor people how improving their life