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IV/
1. We're excited that Nam won a scholarship.
2. When I entered the room, I was surprised at what I saw. 
3. The rain prevented the volunteers from moving the old lady's lawns. 
4. After having done his homework, David went to bed. 
5. Learning how to cook is easy for anyone. 
VII/
2. Before I passed the exam, I had worked very hard for it. 
3. After I had considered what to study, I decided to major in Maths. 
4. After she had written a letter, she went to bed. 
5. After he had checked the price, he bought a radio.
6. After they had argued, they fought. 
7. Before she had a fatal accident, she had gone out for work. 
8. After she had faced the matter, she decided to go away. 
9. Before we wrote the assignment, we had read the book. 
10. After she had watched the film, she wrote a report. 
VIII/
2. Learning a foreign language takes a long time. 
3. Growing your own food is less expensive. 
4. Sitting in one place for so long is uncomfortable. 
5. Smoking here is not allowed.