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phamhongdannhi
2 năm trước
Cho tam giác ABC vuông tại B ( A khác 60 độ). E, F lần lượt là trung điểm của BC và AC. Đường phân giác AD của tam giác ABC ( D thuộc BC ) cắt đường thẳng EF tại M. a) Chứng minh ABD đồng dạng MED. c) Chứng minh BDF đồng dạng AFM. b) Chứng minh DC/DE=AC/ME DE ME d) Chứng minh diện tích ABC = diện tích ABMF
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Exercise: Choose the best answer to complete each sentence 1. Lean the ladder carefully against the wall, otherwise it will down A. You should handle the ladder carefully or you will fall down B. If you did not lean the ladder against the wall carefully, it would fall down C. If the ladder is not leant carefully against wall, it will fall down D. Lean against the ladder or you will fall off the wall 2. If you…………. Your English every day, you’ll speak it fluently A. use B. Will use C. used to D. are used to 3. If I were you, I…….. him as my nephew A. will treat B. would treat C. am treating D. will have treated 4. If Bob……….. with us, he would have a good time. A. had come B. would come C. came D. would have come 5. Mai can’t get the job because she doesn’t speak EL well A. If Mai gets the job, she will speak English well B. If Mai can’t get the job, she doesn’t speak EL well C. If Mai spoke EL well, she could get the job. D. If Mai could get the job, she would speak EL well 6. That man speaks EL fast, so they can’t understand A If that man didn’t speak fast, they could understand B If that man spoke EL slowly, they could understand C Unless that man spoke EL fast, they could understand him D. All are correct 7. Before the Prime Minister leaves New Yorks he ……… several talks A. will have had B. would have C. will be having D. began 8. As soon as ……………. A certificate in English, he will apply for a job A. would get B. got C. gets D. will get 9. If Bob ………. With us, he would have had a good time A. would come B. would have come C. had come D.came 10. Mary didn’t work hard enough, so she failed in her exams A. If Mary work hard enough, she wouldn’t fail in her exams B. Unless Mary worked hard enough, she would fail in her exams C. If Marr didn’t work hard enough she would fail in her exams D. If Mary had worked enough she wouldn’t have failed in her exams 11. Only if you promise to study hard………… to help you A. will I agree B. agree C. I agree D. I will agree 12. If you go away, you…………..write to me,……..you? A. will/won’t B. can/ can’t C. wwould/ wouldn’t D. do/ don’t 13.If the patient doesn’t feel better tomorrow, he’ll have an operation A. Unless the patient feels better tomorrow, he won’t have an operation B.Unless the patient feels better tomorrow, he will have an operation C.Unless the patient feels better tomorrow, he has an operation D. Unless the patient feels better tomorrow, he is going to have an operation 14. You’ll get well quickly if you eat this food A. You can’t get well quickly if you don’t eat this food B. You won’t get well quickly if you don’t eat this food C. You shouldn’t get well quickly if you don’t eat this food D.You don’t get well quickly if you don’t eat this food 15. If it is fine, they will go camping. A. If it is not fine, they won’t go camping. B. If they go camping, it will be fine. C. If they go camping, it is fine. D. If it is fine, they don’t go camping. 16.Unless you promise not to tell anyone, I won’ give you this letter A. If you promise not to tell anyone, I will give you this letter B. If you don’t promise to tell anyone, I will give you this letter c. If you promise not to tell anyone I won’t give you this letter 17. If you don’t finish this exercise, I won’t let you out A. As long as you finish this exercise I won’t let you out B. Unless you finish this exercise I will let you out C. Provided that you finish this exercise I will let you out D. If you finish this exercise I won’t let you out 18. If I could speak Spanish, I ….......... next year studying in Mexico A. will spend B. had spent C. would spend D. would have spent 19. a. If I …...…… the trick with my eyes, I would never have believed it possible. A. don’t see B. didn’t see C. hadn’t seen D. haven’t seen

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