user-avatar
trantrangg248
2 năm trước
Câu 1: cho góc xOy khác góc bẹt lấy các điểm A,B thuộc tia Ox sao cho OA<OB lấy các điểm C,D thuộc tia Oy sao cho OC= OA , OD= OB gọi E là giao điểm của AD và BC. Chứng minh rằng a, AD= BC b, tâm giác EAB= tam giác ECD c, OE là tia phân giác của góc xOy Câu 2: cho tam giác ABC cân tại A ( góc A<90°)
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

giúp mình với mn! REVISION UNIT 10 I. Choose the word in each group that has the underlined part pronounced differently from the rest. 1. .A. celebrate B. abrupt C. plumber D. describe 2. .A. baby B. dumb C. bin D. book 3. .A. place B. plant C. psychology D. plan 4. A. pollute B. accept C. accept D. receipt 5. A. climber B. bomb C. blue D. combing II. Choose a word in each line that has different stress pattern 6. A. protect     B. risky     C. disease     D. pollute 7. A. erosion     B. disappear     C. destruction     D. construction 8. A. nature    B. cancer C. suffer    D. injure 9. A. defence     B. concern     C. pollute     D. threaten 10. A. liquid    B. reveal C. construct     D. destroy III. Choose the best option among A, B, C or D. 11. Each year about fifty hundred species of plants and animals are already being _______ . A. imprisoned   B. polluted   C. eliminated  D. caught 12. The heavy rain has caused _______ in many parts of the country. A. crops B. floods C. water D. soil 13. Half the world's rain forests have already been _______. A. endangered B. eroded C. found D. destroyed 14. This is especially worrying when there are about 3,000 plants with values as medicines against cancer, AIDS, heart _______ and many other sicknesses. A. treatment B. protection C. prevention D. disease 15. Acid rain has caused severe _______ on the hillside. A. erosion B. pollution C. destruction D. circulation 16. Trees, glasses, and other plant life _______ an important part in the natural circulation of water. A. play B. take C. bring D. give 17. A large hydroelectric _______ was built on the River Danube. A. power B. dam C. bank D. wall 18. By cutting down trees we _______ the natural habitat of birds and animals. A. damage B. harm C. hurt D. injure 19.  Man and most animals need a ________ supply of water to live. A. constant     B. flexible     C. polluted     D. valuable 20. There are many________ of plants and animals in danger of extinction. A. damages     B. floods     C. species    D. defence 21._______ taking the train instead of the bus? It's faster. A. How about B. Let's C. Why don't D. Why not 22. We are now facing the possible_______ of several rare species. A. danger B. variety C. existence D. disappearance 23. Last night a tornado swept through Rockville. It _______ everything in its path. A. was destroy B. was being destroyed C. destroyed D. had been destroyed 24. A large hospital _______ in this area now. A. is building     B. is being built     C. build     D. was built 25. A shortage of water is a problem in many parts of the world. In some areas, water ________ from the ground faster than nature can replenish the supply. A. is being taken        B. is taking C. has been taking        D. has taken 26. Deforestation _______ destroying Earth’s plant and animal variety. A. are     B. be     C. is     D. being 27. The photos ________ in a London studio last week. A. have been B. was taken C. have taken D. were taken 28. When the boy ________ the car he was badly injured. A. hit B. was C. was hit by D. is hit by

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team