Giúp em câu 3 nhé mn (mn giúp e luôn phần lưu ý trong câu 3 luôn nhé). Thanks mn ạ ❤❤❤

một tàu thủy chạy xuôi dòng 30km rồi ngược dòng 9km tổng cộng hết 3h . Tings vận tốc của canô khi nước yên lặng . Biết vận tốc dòng nước là 3km/h

Hãy tìm một số trường hợp chuyển nghĩa của các từ: đầu, mũi,tay.

II. TỰ LUẬN ( 7 điểm) Câu 1(4 điểm) a) Hãy chỉ ra chất nào là oxit axit, oxit bazơ trong các oxit có công thức hóa học sau: CaO, SO2, N2O5, CuO, P2O3, K2O, Al2O3, CO2. b) Viết công thức hóa học của các oxit sau: Cacbon monooxit, Natri oxit, Sắt (II) oxit, Đi nitơ oxit. Câu 2 (3 điểm): Đốt cháy hoàn toàn 8,1g nhôm trong bình chứa khí O2. a) Hãy viết phương trình phản ứng xảy ra. b) Tính thể tích khí O2 (ở đktc) đã tham gia phản ứng trên. c) Tính khối lượng oxit tạo thành?

Vì sao nói thực vật trong tự nhiên rất đa dạng và phong phú Giúp mình với nha cảm ơn các bạn

mọi người giúp em với em đang cần gắp em hứa sẽ cảm ơn và 5 vote 20. You shouldn’t leave your shoes here or people will trip over them. A. Don’t leave your shoes here and people won’t trip over them. B. Leave your shoes here or people will trip over them. C. Don’t leave your shoes here or people will trip over them. D. Leave your shoes here and people will trip over them. 21. – Stephanie: “Oh, no! I left my book at home. Can I share yours?” – Scott: “______” A. No, thanks. B. Yes, I do too. C. No, not at all. D. Yes, sure. 7/13 22. – Mike: “Need a hand with your suitcase, Jane?” – Jane: “______” A. That’s very kind of you. C. Not a chance. B. Well done! D. I don’t believe it. 23. – Mike: “So, you have your fifth high-school reunion coming up?” – Lane: “________” A. Oh, the school reunion was wonderful. B. The food at the reunion was excellent. C. Yeah. I’m really looking forward to it. D. No. You’re in no mood for the event. 8/13 Find the ERROR in these following sentences 24. If the boys had took the bus to school, they A B would have arrived on time. C D 25. Had he worked harder, a better job A B would have gotten by him. C D 26. Even though they are among the smallest A B carnivores, weasels will be attacked animal that C are twice double their size. D 9/13 Choose the word that is CLOSEST in meaning to the BOLD part in the following sentence: 27. The oil that discharged into the sea seriously harmed a lot of birds and animals. A. protected B. hunted C. damaged D. saved 28. Together, they cover 75% of our Earth. A. spread B. curtain C. comprehend D. report Choose the word that is OPPOSITE in meaning to the BOLD part in the following sentence: 29. Public health officials have confirmed the first U.S. case of a mysterious coronavirus that has sickened hundreds in China, the CDC says. A. clear B. strange C. difficult D. polluted 30. The plants and animals of the sea fall into three major groups. A. small B. tiny C. subordinate D. unnecessary 10/13 READING 1 Scientists have discovered a (31)..... volcanic ‘lost world’ off the coast of Tasmania. (32)..... on the Commonwealth Scientific and Industrial Research Organisation (CSIRO), vessel ‘Investigator’ made the find (33)..... mapping the seafloor 249 miles east of Tasmania. The project is led by scientists from the Australian National University. CSIRO is Australia’s national science (34)...... A chain of ‘(35)......’, or undersea mountains, were spotted in deep water, offering the first glimpse of a spectacular “underwater world.” 31. A. mysterious B. stunning C. challenged D. huge 32. A. Analysts B. Environmentalists C. Lecturers D. Experts 33. A. when B. during C. while D. if 34. A. agency B. course C. school D. laboratory 35. A. seafood B. seafloors C. seasons D. seamounts 11/13 READING 2 Most people are afraid of sharks, but they usually do not know very much about them. There are more than 350 kinds of sharks, and all of them are meat eaters. Sharks are useful because they eat sick fish and keep the oceans clean. Sharks do not have ears. However, they can "hear" sounds and movements in the water. Any sound or movement makes the water vibrate. Sharks can feel these vibrations, which help them find food. They also use their large eyes to find food. Most sharks see best in dim light. They often hunt for food at dawn, in the evening, or in the middle of the night. Scientists want to learn more about sharks for several reasons. For example, cancer is common in many animals, especially in people. However, it is rare in sharks. Scientists want to find out why sharks almost never get cancer. Maybe this information can help people prevent cancer too. 36. According to the passage, sharks are useful because _________. A. they are very big C. they are meat eaters B. they clean the oceans D. they eat fish 12/13 37. Sharks can find food because they can _____. A. feel vibrations and hear with their ears B. see with their eyes and hear with their ears C. feel vibrations and see with their large eyes D. hear very well with their large ears 38. Most sharks hunt for food at night because ______. A. they see best in dim light C. there is more food then B. they are hungry at night D. other fish are sleeping 39. According to the passage, research on sharks may help _______________. A. people know how to prevent cancer B. animals prevent cancer C. people find a cure for AIDS D. sharks live longer 13/13 40. The passage is most likely to be taken from ____. A. a teenager's diary. C. a essay on marine life . B. a magazine for business. D. a study on sharks

S=1=2-3-4+5+6-7-8+9+10-11-12+...+298+299-300+301+302

Cho góc nhọn xOy. Trên tia Ox, Oy lấy tương ứng hai điểm A và B sao cho OA = OB. Vẽ đường tròn tâm A và tâm B có cùng bán kính sao cho chúng cắt nhau tại hai điểm M, N nằm trong góc xOy. Chứng minh rằng : a) OMA = OMB và ONA = ONB ; b) Ba điểm O, M, N thẳng hàng ; c) AMN = BMN ; d) MN là tia phân giác của góc AMB. Mn giúp e lm với e đg cần gấp ạ Mơn nhìu

Em hãy kể tên các nhân vật anh hùng đã lãnh đạo các cuộc khởi nghĩa chống lại ánh đô hộ của phong kiến phương bắc ?

Chế độ cai trị của các triều đại phong kiến phương Bắc đối với thế kỉ I đến TK VI ? Em có nhận xét j về sự thay đổi này ?