Bài 1:Cho tam giác ABC vuông tại A. Đường phân giác của góc B cắt AC tại D. Từ D kẻ DE vuông góc với BC . Đường thẳng ED cắt BA tại F. a/. Chứng minh . Từ đó suy ra ? b/. Chứng minh BD là đường trung trực của AE c/. Chứng minh BD vuông góc với CF

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Exercise 1. Put the correct form of the word in brackets. 1. I’m not tall enough to play volleyball. I wish __________ tall and strong. (I/ be) 2. I’m fed up with this rain. I wish ______________ raining. (it/ stop) 3. My grandparents don’t like living in the city. They wish ______________ in the countryside. (they/ live) 4. It’s a difficult question. I wish ______________ the answer. (I/know) 5. I wish ______________ here. She’d be able to help us. (Ann/ be) 6. Aren’t they ready yet? I wish ______________. (they/ hurry up) 7. It would be nice to stay here. I wish ______________go now. (we/ not have to) 8. It’s freezing today. I wish ____________ so cold. I hate cold weather. (it/ not be) 9. What’s her name again? I wish ______________ remember her name. (I/ can) 10. You’re driving too fast. I wish ______________ a bit. (you/ slow down) 11. What I said was stupid. I wish ______________ anything. (I/ not say) 12. I should have listened to you. I wish ______________ your advice. (I/ take) Exercise 2. Rewrite the following sentences: 1. He smokes too much; that’s why he can’t get rid of his cough. => If…………………………………………………………………………. 2. She is very shy, so she doesn’t enjoy the party. => If…………………………………………………………………………. 3. He doesn’t take any exercises. He is so unhealthy => If…………………………………………………………………………. 4. We can’t get the ticket because I don’t have the right change. => If…………………………………………………………………………. 5. Study hard or you won’t pass the exam. => If…………………………………………………………………………. 6. He didn’t revise all his lessons, he failed the exam. => If he……………………………………………………………………… 7. Leave me alone or I’ll call the police. =>Unless……………………………………………………………………. 8. He is very bad-tempered, that’s why his wife left him soon after marriage. => If he……………………………………………………………………… 9. Don’t tell lies to your boss or you’ll be fired at once. => If…………………………………………………………………………. 10. I didn’t eat lunch, I feel hungry now. => If I…………..……………………………………………………………