Khi nung V lít butan với xúc tác thích hợp thu được hỗn hợp X gồm CH4, C2H6, C3H6, C2H4, C4H8, H2, C4H10 dư. Tỉ khối hơi của X so với H2 bằng 19,76. Hiệu suất của phản ứng nung butan khoảng : A. 50,33%. B. 66,67%. C. 46,76%. D. 33,33%.

Thiết kế sơ đồ cấu tạo và chức năng của hệ thần kinh của bài Thần kinh và giác quan (vào vở)

Câu số 2 nha mn đề ôn thi vào 10 Nó là viết đoạn văn nha Cảm ơn mọn người nhiều ạ <3

Giúp mình với nhé. Mình cảm ơn Bài tập 1:tìm trạng ngữ trong câu sau đây và cho biết ý nghĩa của chúng? a.Từ hồi tiền của trong nhà kém sút và bà Tú phải xuôi ngược vất vả, ông bỏ mất tính thích giao du ngày trước, để hết tâm trí mỏi mệt vào tập sách nho và bộ ấm chén chè tàu. (Thế Lữ) b. Mùa nước lớn muộn này, cái giống sen nhật trôi lang thang mặt nước vẩn vơ như chim vỡ tổ. (Tô Hoài) c. Bước chân vào nhà, tự nhiên Liên thấy lo sợ d.Trước khi đi nó còn cho tôi ba đồng bạc, ông (Nam Cao)

giúp minhf với mình đang cần gấp

động cơ đốt trong có gây ô nhiễm môi trường k?em sẽ làm j để giảm ô nhiễm môi trường do động cơ đốt trong gây ra?

Tổ tiên của Bò sát là loài nào?

Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following questions. 29. Tom is talking with Alex about the weekend Tom: Have a nice weekend ! – Alex:.................................. A. Ok. Yes, please B. Thank you. The same to you C. It’s not very long now D. No, thanks 30 . Mary is asking Linda to stay at her house. Mary :“Would you like to stay the night?” - Linda: “ __________________” A. Are you sure? B. Oh, that’s very kind of you. C. I don’t know. D. It’s far from here. Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part among A, B, C or D that needs correcting. 31. When she arrive at the station, the train had left,so she couldn’t catch it. A B C D 32. The farmers had to work hardly in the fields all day. A B C D 33. Nick didn't understand the lesson because he couldn't do the homework last night. A B C D Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks I'm going to give you the details of our camping trip next week. The coach will be outside the school on Monday morning at 7.30 and we will (34)………….at 7.45 so don't be late. There'll be room on the coach for one bag, so please don't bring more than one bag or suitcase. You don't need t bring tents or food as that's all (35)…………….for us. It is often hot during the day, but it turns cold at night so bring warm clothes. If we're lucky though, the sun will shine and we'll be (36)…………..to use the outdoor pool on the site so don't forget your swimming things. The campsite is in the (37) ………..of the countryside so if you've had enough fresh air by then, you may want to go shopping in the nearest town about four kilometers away. There's plenty to do there and there's a bus that stops outside the Post office in the village down the road. I'll (38) ………….. it to you when we get there. 34. A. set up B. set off C. turn up D. turn off 35. A. charged B. delivered C. bought D. provided 36. A. able B. capable C. possible D. desirable 37. A. core B. behind C. middle D. among 38. A. give B. point C. shoot D. get Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions The relationship between a teacher and a student can be either good or bad, helpful or harmful. Either way, the relationship can affect the student for the rest of his life. In order to have a good teacher-student relationship, it is important that the teacher and the student respect each other. If the teacher is too strict, he frightens the student. The student will not learn well. On the other hand , if the teacher is too friendly and permissive, the student may become lazy and stop working hard. The teacher’s attitude and approach should be between these two extremes. He should encourage the student without forcing or pushing him to learn. He needs patience and understanding. It is part of the teacher’s job to help develop a good positive attitude in his students. As for the student, in order to have a good relationship with his teacher, he must always show his proper respect. He should be eager to learn and willing to work hard. If he learns from the teacher modestly, he will be able to profit fully from his teacher’s knowledge and assistance. 39. The relationship between a teacher and a student is considered very important because it.. A. can be either good or bad B.it’s very harmful to the student. C. makes the student unsafe D.has a great influence on the student’s life. 40. One of the most important factor for a good teacher-student relationship is the mutual….. A. responsibility B.respect C. support D. understanding. 41. In order to have a good teacher-student relationship, the teacher _____. A. should force the student to learn B.needs patience and understanding. C.should be too friendly and permissive D.ought to be strict. 42. In order to have a good relationship with the teacher , the student ………. A.must be a hard-working person B.must always support the teacher C.must always be a gifted person D.must always be an excellent person. 43. According to the passage it’s true that……….. A. the student always profit fully from his teacher. B.the student must thank for his teacher’s knowledge and assistance. C.the student must always show his proper respect to his teacher. D.the teacher himself needs to develop a good positive attitude. giúp mình gấp mình vote 5s cho

Giúp mình giải ạ 6.8=(5×2)+(6×n)+(9×2)+(10×1)+(2+n+2+1)

Đầu năm 1975, Bộ Chính trị Trung ương Đảng đề ra chủ trương kế hoạch giải phóng hoàn toàn miền Nam trong bối cảnh thuận lợi nào? A: Quân Mĩ và quân Đồng minh đã rút khỏi miền Nam, ngụy mất chỗ dựa. B: Mĩ cắt giảm viện trợ cho chính quyền Sài Gòn. C: So sánh lực lượng thay đổi mau lẹ có lợi cho cách mạng. D: Khả năng chi viện của miền Bắc cho tiền tuyến miền Nam suy giảm.