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1. It's interesting that he thought of making toys from used paper.
2. It's over 20 years since he last came back to his home village. 
3. I have never seen such a strange film. 
4. I'd rather you didn't interrupt me while I am speaking. 
5. If you don't get up now, you'll be late for school. 
6. We haven't met each other for ten years. 
7. It's difficult to find accommodation at busy time in Da Lat. 
8. Tennis used to be an indoor game. 
9. My friend likes living in the countryside better than living in the city. 
10. Lan is the most intelligent student in my class. 
11. Is this the first time you have played a computer game? 
12. The Statue of Liberty was presented to the United States by France in 1876.
13. The water wasn't warm enough for the children to swim in. 
14. It's ages since he chatted with his friends through the internet. 
15. Experiments on animals should be stopped.