17. People say that he is very rich A. He is said to be very rich. B. He is said to have been very rich. C. He was said to be very rich. D. He was said to have been very rich. 18. People think that he was born into a rich family. A. He is thought to have been born into a rich family B. He is thought to be born into a rich family. C. People think his family is rich, so he was born. 19. People rumoured that her husband had died in the battle. A. Her husband is rumoured to die in the battle. B. Her husband died in the battle, and it is the truth. C. People knew that her husband died in the battle. D. Her husband was rumoured to have died in the battle. 20.. They say that many people are homeless after the tsunami. a. They say many people to have been homeless after the tsunami. b. They say many people to be homeless after the tsunami. c. Many people are said to have been homeless after the tsunami. d. Many people are said to be homeless after the tsunami. 21. They know that the Prime Minister is in favour of the new law. a. The Prime Minister is known to have been in favour of the new law. b. They know the Prime Minister to be in favour of the new law. c. The Prime Minister is known to be in favour of the new law. d. They know the Prime Minister to have been in favour of the new law.

Trộn 2 lít dung dịch rượu êtylic có nồng độ 1M, vào 3 lít dung dịch rượu êtylíc có nồng độ 2M. Tính nồng độ mol của dung dịch rượu êtylíc sau khi pha trộn.

Giải giúp mình bài 2 với ạ. Rõ ràng nha. Mình đang cần gấp

Hai thành phố A và B cách nhau 100km.Lúc 7h, một ôtô khởi hành ở A chuyển động thẳng đều về B với độ lớn vận tốc 80km/h. Sau đó, một xe gắn máy khởi hành ở B chuyển động thẳng đều ngược chiều với xe ô tô với độ lớn vận tốc 40km/h. Hai xe gặp nhau ở vị trí cách B 20km . Hỏi xe gắn máy khởi hành lúc mấy giờ?

Giải giúp mik với mik đang cần gấp ạ

Zẽ chibeo/anime ik Y/C: ko có, sao cx đc nên không cần hỏi N/L: xem lại tranh hồi xưa nhìn mà phát khóc luôn ấy, đã vậy còn lên mặt, tạo dramu nữa chứ, xem lại thấy mình khùng thật sự ;^;

cần gấp ai giúp vs ạ ai giúp vs

Cho góc xOy= 60 và điểm A nằm trong góc đó. Gọi B, C lần lượt là hai điểm đối xứng với điểm A qua Ox Oy a) Chứng minh tam giác BOC là tam giác cân. Tính các góc của tam giác đó. b) Tìm điểm I trên Ox và điểm K trên Oy sao cho tam giác AIK có chu vi nhỏ nhất.

25. They report that over 200,000 people were killed in the tsunami. a. Over 200,000 people are reported to have been killed in the tsunami. b. Over 200,000 people are reported to be killed in the tsunami. c. Over 200,000 people are reported to have killed in the tsunami. d. Over 200,000 people are reported to kill in the tsunami. 26. They say that three men were arrested after the explosion. a. Three men are said to be arrested after the explosion. b. Three men are said to have been arrested after the explosion. c. Three mend are said to have arrested after the explosion. d. Three men are said to arrest after the explosion. 27. People say that he is the most experienced teacher of English. a. He is said to be the most experienced teacher of English. b. He is said the most experienced teacher of English. c. He is to be said the most experienced teacher of English. d. That he is the most experienced teacher of English is said by people. 28. Reagan _______an actor years ago. A. is said to be B. was said being C. was said have been D. is said to have been 29. It _______that learning a foreign language_______a lot of time. A. says/ is take B. is saying/ has been taken C. is said/ takes D. was said/ was taken

Tại sao khi ánh sáng chiếu vào 1 vật nó lại hắc ánh sáng chiếu vào nó mà truyền đến mắt ta?