cho 2 tia oy,oz cùng thuộc 1 nửa mp có bờ chưa tia ox sao cho số đo góc xoy=30o và số đo góc xoz=120o a)yoz? b)vẽ om sao cho số đo góc xom=60o.phải có điều kiện gì để om là tia pg của góc xoz?tại soa? làm nhanh e sẽ cho ctlhn+cảm ơn+5*(nma phải đúng ạ)

Làm giúp mình bài này với ạ Mình cảm ơn

Giải thích "Tại sao diễn thế thứ sinh có thể hình thành nên quần xã tương đối ổn định hay quần xã suy vong ở giai đoạn cuối"?

1. Air......................, together with littering, is causing many problems in our cities today. A. pollute B. pollution C. polluting D. polluted 2. The road in front of my office is always .................... when it rains heavily. A. to flood B. flooding C. flood D. flooded 3. Singapore is famous for its .................... and green trees. A. cleanliness B. cleanly C. cleaning D. clean 4. In some English speaking countries, turkey and pudding are ............... food at Christmas. A. national B. historical C. traditional D. possible 5. The USA has a population of 304 million, and it’s the third ............. country in the world. A. smallest B. largest C. narrowest D. highest 6. The roof of the building .......................... in a storm a few days ago. A. damaged B. was damaged C. has damaged D. has been damaged 7. A severe tropical ...................... is called a typhoon. A. drought B. rain C. flood D. storm 8. As soon as the floodwater ...................... down, people ........................ their houses. A. went - cleaned B. had gone – cleaned C. went - had cleaned D. had gone – had cleaned 9. If I were you, I ..................... do something to prevent him from littering. A. would B. did C. will D. do 10. Earth .................. by the gravity of the Sun and orbits around it. A. holds B. is held C. is holding D. held 11. By the time we ........................ to the cinema, the film had started. A. gets B. had got C. has got D. got 12. When the policeman came there, the robber .................. A. had left B. has left C. left D. was left 13. All people who were without homes in the flood were provided with .................. accommodation. A. short B. temporary C. present D. instant 14. Seven of ten people prefer face-to-face ..................... when having a date. A. language B. contact C. code D. sign 15. When thermal pollution happens, the water temperature in streams, rivers, lakes and oceans ........................ A. changes B. keeps C. remains D. stays

11 giờ kém 15 phút đến 11 giờ 20 phút là mấy phút?

Cho mình bỏi 3 chữ B, I, U ngĩa là gì vậy ạ?

Nhanh giúp em ạ... Đề bài: Viết lại câu 1.They last saw their old teacher in 2020 (Have) 2.She didn't word hard, so she failed the exam (BECAUSE) 3.Don't play qutside, or you will be sick. (IF)

Nhận biết: stiren, phenol, ancol etylic và benzen

Câu 5. Đặc điểm nào dưới đây có ở chim bồ câu nhà? (1) Chim mái mỗi lứa chỉ đẻ 2 trứng. (2) Chim mái không có cơ quan giao phối. (3) Chim trống và chim mái thay nhau ấp trứng. (4) Có kiểu bay lượn. (5) Không có răng. (6) Nuôi cơn bằng sữa diều. A. 1, 2, 4, 6. B. 1, 3, 5, 6. C.2, 4, 5, 6. D.1, 2, 3, 4.

B. Questions: 1. Where will our future house be? …………………………………………………………………………………………………………… 2. What will it be surrounded? …………………………………………………………………………………………………………… 3. Is ocean water salty? ……………………………………………………………………………………………………………