Cho tam giác ABC cân tại A. Lấy điểm D thuộc cạnh AC, lấy điểm E thuộc cạnh AB sao cho DE//BC. Gọi O là giao điểm BE,CD. Chứng minh AO vuông góc BC. Cứu mình với, mình đang vội quá!

Bài 9:viết số lớn nhất và nhỏ nhất bằng cách dùng cả 10 chữ số khác nhau(mỗi số chỉ được viết 1 lần) Bài 12: Tính các số tự nhiên chẵn có 4 chữ số Bài 13:muốn viết tất cả các số tự nhiên từ 100 đến 999 phải dùng bao nhiêu chữ số 9

giúp mình vớiiiiiiiiiiiiiiiiiiiiii

giúp mình hai câu này ạ mình cảm ơn

Mọi người giúp em với ạ em đang cần gấp

Cứu em zớiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

Bài1: Bạn Tuấn cao 134 cm, Bạn Hồng cao hơn bạn Tuấn 8cm, Bạn Linh thấp hơn bạn Hồng 4cm. Hỏi trung bình mỗi bạn cao bao nhiêu xăng-ti-mét?

Combine these sentences using: though, although, even though 1. Lion dancing is very popular in Viet Nam. My friend Anny does not enjoy it. => 2. Bob always walks to work. He is living in the city. => 3. My house is near the beach. I rarely go swimming. => 4. My brother is working in Ha Noi. He comes home on every public holiday. => 5. Paul is an Australian, he enjoys Vietnamese New year. => 6 Most children go to see the firework show, Linh and Mai stay home watching TV. => 7. Nick used to smoke. He seems to be in good health. => 8. I couldn’t sleep. I was tired. => 9. Henry’s friend is a millionaire. He hates spending money. => 10. We couldn’t get tickets. We queued for an hour. help me với mn ơi khó quá

tính nhanh 23 x 7 + 17 x 7 = help em với vote 5 và cảm ơn

Supply the correct forms of the word in parentheses. 1. Phuong Linh arranged flowers the most .......................(attract) in the contest. 2. It is a contest in which ....................(participate) have to read two poems in English. 3. .......................(environment) are concerned about the use of dynamite to catch fish. 4. Years later, she passed me in the street without even a small sign of .......(recognize). 5. Nam put ................(press) on that towel to stop the bleeding. 6. After many years of ............(fail), Edison finally succeeded in inventing the light bulb. 7. We use first-aid in order to ease the victim’s pain and ......................(anxious). 8. She felt ....................(relief) after she passed the exam. 9. You’ll meet the tour guide on your ..................(arrive) at the hotel. 10. We can take buses or trains to Northern ......................(destine) of Nha Trang. 11. Sapa is considered the most beautiful .......(mountain) resort in the north of Viet Nam. 12. It’s now high time you knew how to dress and ....................(dress) yourself. 13. We are having a good time here. People on the island are very friendly and ...........(hospitality). 14. The police are interested in the sudden ............(appear) of the valuable painting. 15. I wrote .............(end) letters of application but I got no reply. 16. A fairy appeared and ...................................... ( MAGIC )changed her old clothes 17. The tiger wanted to see the farmer’s .................................. ( WISE ) 18. In that story, the prince got ........................( MARRY )to a poor girl 19. Let me get an .................................... ( APPLY ) form and I can fill out 20. He was ............................... ( FOOL ) to say that English is helpless