có hỗn hợp bột CaCO3 và CaSO4. Nêu cách để xác định thành phần phần trăm theo khối lượng của mỗi chất trong hỗn hợp. viết phương trình hóa học (nếu có)

Cho phân thức A= x^2 + 6x + 9/x^2-9 Câu hỏi: 1, Với giá trị nào của x thì giá trị của phân thức A xác định? 2, Rút gọn phân thức A. 3, Tính giá trị của biểu thức A tại x = 9

VI.Read the passage and choose the correct answers (A, B, C or D) to fill in the blanks. Nam is eleven years old and he starts a new secondary school this year.Nam’s old school is near his house but very small.Although he (34)________ the school,there is no football fleld there.At his new school,there is a bis fleld where students can play football, badminton and basketball.Sometime,other schools (35) _______ Nam’s school and compete with his school on the fleld.There is also a football team and basketball team at Nam’s new school. (36) ________ an avid football fan,Nam is training hard to join the team.It’s hard to get in (37) ________ there are a lot of students who want to be part of the team.Nam will try his best (38) _________ the try-out next week. 34. A. dislikes B. leaves C. loves D. needs 35. A. visit B. visits C. visiting D. to visit 36. A. Be B. To have been C. To be D. Being 37. A. although B. because C. because of D. but 38. A. at B. on C. behind D. for VII.Read the passage ad choose the correct answers. Located in a small village outside Central City,ASIA Care is a secondary school with no more than 200 students.There are totally 11 classes ranging from grade 6 to 9. Despite being small,ASIA Care has a spacious campus.It’s large enough for students to play sport and hold many events .On the last Saturday of every month,a quiz contest takes place on campus.It’s a friendly competition between students from different classes.The participating students answer many questions to tes their common knowledge as well as their skillsin many subjects like maths and English. 39. What is the location of ASIA Care? A. Near a small village. B. Near the Central City. C. Near the middle of the city. D. Near a campus 40. Which grade are students of ASIA Care in? A. Grade 2. B. Grade 11. C. From grade 6 to grade 9. D. From grade 6 to grade 11. 41. What is the meaning of the word “spacious” underlined in the passage? A. Large and with plenty of space. B. Too small. C. Clean and tidy. D. Safe and secure. 42. What happens on campus by the end of each month? A. A sports competition is held. B. An event of quiz club is hosted. C. A quiz contest is organised. D. A maths contest is organised. 43. Which of the following is NOT mentioned in the passage? A. The quiz contest is held for students of ASIA Care. B. The participants of quiz contest must use common knowledge and skills of many subjects. C. English is one of the topics in the quiz contest. D. Sports is one of the topics in the quiz contest.

giải gấp cho mik nha , sẽ vote công bằng 1. lập dàn ý miêu tả nhân vật Dế Mèn trong văn bản "Bài học đường đời đầu tiên"

Biết rằng 8g Natri hidroxit NaOH tác dụng với 19,6g axit sunfuric H2SO4 tạo thành Natri sunfat Na2SO4 và 3,6g nước . lập PTHH của phản ứng . tính khối lượng của Natri sunfat Na2SO4

Cho hai danh từ sau: ngôi nhà, học sinh a) Hãy tạo thành cụm danh từ với mỗi danh từ trên. b) Đặt câu với hai cụm danh từ vừa tạo thành.

IV.Choose the best word or phrase (A, B, C or D) to complete each sentences. 16. Her children must wear their when they go to school every day. A. coat B. jeans C. uniform D. T-shirt 17. He’s a hard-working student.He usually learns by heart all new English at home. A. homework B. lessons C. vocabulary D. schoolbags 18. Her father is a(n) teacher.He often does some interesting experiments in front of his class. A. literature B. science C. English D. music 19. I am using my to draw a circle carefully in the art lesson at present. A. ruler B. notebook C. pencil sharpener D. compass 20. Nga and Mai are looking up some unknown words together on a paper in the library now. A. dictionary B. computer C. workbook D. map 21. You should put your warm clothes now because the weather is so cold. A. on B. at C. up D. away 22. He wants to be stronger,so he does every weekend morning. A. badminton B. football C. jog D. judo 23. I’m having school ____ with a bolled egg, some fried rice and some salads. A. day B. thing C. lunch D. ground 24. My brothers play ____ very skillfully. I hope I will play it well like them. A. piano B. the guitar C. karate D. the football 25. I regularly ___ jogging with my friends in the park. It helps improve our health. A. do B. play C. have D. go 26. Water ____ at about 100C. I learn about it from my previous physics lesson. A. boils B. boil C. is boiling D. are boiling 27. My mother and my sister ____ swimming twice a week. A. so B. goes C. are D. is 28. Look at him! He ___ morning exercise with his father. A. does B.is doing C. learns D. is learning 29. They usually pplay table tennis every afternoon, but today they ____ with their parents to prepare for the next exams. A. is studying B. study C. are studying D. studies 30. Their sister _____ alone at home now. She ____ with her friends in the park. A. is/is playing B. is/ isn’t plpaying C. isn’t/ isn’t playing D. isn’t/ is pplaying V. Choose the best response ( A, B, C or D) to complete each conversation 31. - How nice your schoolbag is! - _________________________ A. I bought it yesterday. B. Thanks a lot. C. It’s a present from my father. D. You’re welcome. 32. -Why are you interested in learning English? -__________________________ A. Because it helps me communicate with international frends. B. I think I’m very good at speaking English. C. I’m attending an English club. D. Because I’m studying in a boarding school. 33. -Would you like to go to the library? -____________________________ A. Not at all. B. You’re so kind,but I can’t go with you. C. Yes,reading books is my favourite hobby. D. Sorry, I can’t. I’m busy now.

Bài tập 2: Hiện nay, trong một số gia đình có tình trạng chồng ngược đãi, đánh đập hành hạ vợ. Trước tình trạng đó, nhiều người cho rằng đó là chuyện bình thường, là việc riêng của vợ chồng, gia đình người ta, không nên can thiệp. Em có tán thành quan niệm đó không? Vì sao? Bài tập 3: Em tán thành hoặc không tán thành với hành vi nào sau đây? Giải thích vì sao em đồng ý hoặc khô

Tính giá trị các biểu thức sau : 1, A = 1 + 3 + 3^2 + 3^3 + ..... + 3^2020 2, B = 6^2 + 6^4 + 6^6 + .... + 6^1010 3, C = 1 - 2 + 2^2 - 2^3 + ..... - 2^2011 + 2^2012 4, D = -2 + 2^2 - 2^3 + 2^4 - ..... - 2^2019 + 2^2020 Mình sẽ vote cảm ơn và bình chọn câu trả lời hay nhất cho bạn nào trả lời nhanh và chính xác nhé

Mọi người giúp mình bài khoanh này với ,mình hứa sẽ vote đầy đủ