1. He always studies hard. He doesn't want to get bad marks_
=> He always studies hard so as not to get bad marks
2. Minh is underlining important words. He wants to remember them better.
=> Minh is underlining important words in order to remember them better.
3. I stopped working. I wanted to go to sleep.
=> I stopped working so as to go to sleep.
4. I went to the bookstore yesterday. I bought some new English books.
=> I went to the bookstore yesterday so as to buy some new English books.
5. Lan wears warm clothes. She won't catch a cold.
=> Lan wears warm clothes in order not to catch a cold.
6. Playing sports is good for your health
=> It's good for your health to play sports
7. That question is very easy to answer
=> It is very easy to answer the question
8. Working alone is not easy for us
=> It is not easy for us to work alone
9. It is useful for us to watch news every day
=> Watching news every day is useful for us
10. It is very difficult to lock that window
=> Locking that window is very diffcult