cho tam giác ABC vuông tại A. đường cao AH . tia đối HB lấy D sao cho HB=HD . DK vuông góc với BC(K thuộc AC). O là trung điểm BC. chứng minh OA vuông góc BK

Cho đường tròn (O; R). Vẽ hai điểm A và B thuộc đường tròn sao cho AB = R. Gọi α là số đo cung lớn AB thì α = ?° (Chỉ điền số làm tròn tới hàng đơn vị vào ô trả lời, ví dụ: 120)

Cho 25 gam dung dịch hòa tan NaBr và CaCl2 có tổng nồng độ là 13% vào 180 ml dung dịch AgNO30,5M. Lọc, tách kết tủa, thêm vào nước lọc một lượng dư HCl thì thu được 5,74 gam kết tủa. a. Viết tất cả các phương trình phản ứng xảy ra. b.Tính thành phần phần trăm theo khối lượng muối trong hỗn hợp ban đầu.

Cho tam giác ABC vuông cân tại A, M là trung điểm của BC. Trên cạnh AB lấy điểm E, trên cạnh AC lấy điểm F sao cho . So sánh AE và CF

Viết lại câu sao cho nghĩa không đổi: The film was too boring for you to watch. -> The film was so .........................................

Cho tam giác ABC có AB =AC . Gọi M là trung điểm của BC . Chứng minh răng AM vuông góc với BC

7. Life in the country is different ______ life in the city. A. from B. of C. to D. with 8. “Can you help me to carry this box?” – “______”. A. No, thanks B. I think so C. Yes, I’d love to D. Sure 9. They often come to see their friends on Sunday, ______? A. do they B. are they C. don’t they D. can they 10. My mother came into my room while I ______ television. A. am watching B. was watching C. watch D. watched 11. She doesn’t know the man ______ sent her this letter. A. which B. who C. whom D. whose 12. ______ she is not happy, she always tries to smile. A. So B. However C. Although D. And 13. His business is growing so fast that he must take ______ more workers. A. up B. on C. in D. over 14. If Nam comes to England, it’ll be a good ______ for him to improve his English. A. opportunity B. possibility C. advantage D. experience 15. He taught me how ______ the new computer. A. starting B. to start C. start D. started

Cho tam giác DEF. Đường trung trực của đoạn thẳng DE cắt EF tại I. Trên tia đối của tia ID lấy điểm K sao cho IK = IF. Chứng minh DE // KF

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Exercise 1. Fill in the blanks with WHO, WHICH or THAT: 1. The men _______ lives next-door are English. 2. The dictionary _______ you gave me is very good. 3. Do you know the girls _______ are standing outside the church? 4. The police are looking for the thieve _______ got into my house last night. 5. The chocolate _______ you like comes from the United States. 6. I have lost the necklace _______ my mother gave me on my birthday. 7. A burglar is someone _______ breaks into a house and steals things. 8. Buses _______ go to the airport run every half hour. 9. I can’t find the key _______ opens this door. 10. I gave you a book _______ had many pictures. 11. I don’t like the boy _______ Sue is going out with. 12. Did you see the beautiful dress _______ she wore yesterday. 13. The man _______ she is going to marry is very rich. 14. This is the bank _______ was robbed yesterday. 15. He wore a mask _______ made him look like Mickey Mouse. Exercise 2. Fill in the blanks with WHO, WHICH or WHOSE: 1. He arrived with a friend ______ waited outside in the car. 2. The man ______ mobile was ringing did not know what to do. 3. The car ______ the robbers escaped in was a BMW. 4. The woman ______ daughter was crying tried to calm her down. 5. The postman ______ works in the village is very old. 6. The family ______ car was stolen last week is the Smiths. 7. The cowboy ______ is wearing a red shirt looks very funny. 8. A bus is a big car ______ carries lots of people. 9. The volunteers, ______ enthusiasm was obvious, finished the work quickly. 10. Children ______ like music are often good at mathematics. 11. The engineers ______ designed the building received an award. 12. The girl ______ recited the poem is my niece. 13. The townspeople, __pride in their community is well- known, raised enough money to build a new town hall. 14. The Pacific Ocean, ____ might have been crossed by raft during the Stone Age, is the world’s largest ocean. 15. The newspaper to ______ we subscribe is delivered regularly.