Đốt cháy bột 1,6615 gam Al trong bình khí Cl2 dư, sau khi phản ứng xảy ra hoàn toàn khối lượng chất rắn trong bình tăng 4,26 gam. Tính H phản ứng.

giải phương trình (x-1)^3 + (x-2)^3 = (2x-1)^3 giúp mị với các tình yêu mị nghĩ đặt x-1=a nhưng mị vẫn ko giải ra đc T^T

hai đoạn dây dẫn thẳng dài đặt song song với nhau trong không khí cách nhau 1 khoảng 20cm. Dòng điện qua dây thứ nhất có cường độ 5A. Trên mỗi mét chiều dài của dây dẫn chịu tác dụng một lực F=2X10^-5 N

giúp mình với a... Mình cảm ơn nhiều...

làm giúp em cả phần 1 nhé các anh chị

Chế nào vẽ giúp tui, một bạn Bảo Bình nữ Đẹp nha!!!!!

Viết lại câu văn sau cho sinh động băng cách sử dụng biện pháp so sánh: 1.Cây phượng vĩ ở cổng trường đã nở hoa. 2.Bé có đôi mắt đen tròn, hai má ứng hồng. 3.Sau trận ốm, nó rất gầy. Mình cần rất gấp bài này ai làm hứa cho 5 sao

Để nhớ bài lâu, em phải học tập như thế nào? Giải thích cơ sở khoa học của phương pháp học tập đó? Giải chi tiết hộ em, chủ yếu là phần giải thích cơ sở

II. Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the 1. While I walk past the park, I saw some childrenplay football. 2. After John eats dinner, he wrote several letters and went to bed. 3. What did you do at 9 o'clock last night? I phoned you but nobody answered. 4. By the time I arrivedat the station, the train has already left. 5. Ann and Susan have knowneach otherduring they were at school. 6. She has disappeared three days ago, and they are still looking for her now. 7. After Mrs. Wang had returnedto her housefrom work, she was cooking dinner 8. It’s the first time I sawthis film 9. After he graduatesfrom university, he joined the army. 10. Up to now, there had beenno woman being chosen the US president. 11. After Mrs. Wang had returnedto her housefrom work, she was cooking dinner. 12. Jimmy threw the ball high in the air, and Betty catching it when it came down. 13. Linda has worn her new yellow dress only once since she buys it. 14. Last week Mark told me that he got very bored with his present job and is looking for a new one. 15. Having fed the dog, he was sat down to his own meal. 16. When I turned on my computer, I was shockedto find some junk mail, and I justdelete it all. 17. The boss laughed when the secretary has told him that she reallyneeded a pay rise. 18. Debbie, whose father is an excellent tennis player, has been playing tennis since ten years. 19. I have seenlots of interesting places when I went on holiday last summer. 20. When my cat heard a noise in the bushes, she stopped moving and listenintently.

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. 15. Almost half of turtles and tortoises are known to be threatened with A. extinct B. extinction C. extinctive D. extinctly is the natural environment in which a plant or animal 16. lives. A. Habitat Breeding B. Reserve C. D. research 17. Panda is one of the species which are currently of extinction danger A. on B. in C of D. with is the existence of a wide variety of plant and animal 18. species living in their natural environment. A. Biodiversity B. Conservation C. Urbanization D. Destruction It isn't 19. “Do you have to buy this hat" --“ No, I necessary." A. mustn't B. don't need C. needn't D. won't 20. You A. need _keep it secret or they’ll kill you. C. may B. can D. must