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1. The house is so expensive that they can't buy it.
2. I have difficulty in learning English grammar.
3. He took his umbrella because it was raining.
4. My grandfather is old, so he cannot work very hard.
5. I wish he wouldn't be absent from the class discussion.
6. I wish I could travel to Dalat by train.
7. It took him 20 minutes to type her lesson plan.
He spent 20 minutes typing her lesson plan.
8. He's fond of wearing modern clothing at work.
9. Doing this exercise is not easy.
10. My father used to work for the company.
11. If only I didn't stay in a noisy room.
12. Because Nga is sick today, she can't go to school.
13. It is such a difficult test that I can't do it.
14. It only takes three hours to fly from HCMC to Singapore.