Cho 15,6 gam hỗn hợp gồm Al và Al2O3 tác dụng với đe HCl dư thubđc 6,72l khí ở đktc Tính % khối lượng Al2O3 trong hỗn hợp đầu

Giúp mình nhanh nha mọi người mình cần gấp bai 2 thui nha

Khó quá à (＃｀д´)ﾉ ko biết làm (｡ŏ﹏ŏ)

Bài 1: Rút gọn các phân số sau: a) 33/55 b) -56/72 c) 15/-105 d) 3.14/7.9 e) 9.5 - 9.3/18

Cho tam giác DEF nhọn,DE<DF.Lấy M thuộc cạch DE,N thuộc cạnh DF sao choMN//EF.Cho biếtDM=2cm,ME=2cm,DN=3,5cm.TínhNF?

Circle the letter A, B, C or D to indicate the sentence that expresses the best meaning formed by the given words. Question 38. My friend/ never/ ride/ horse/ before. A. My friend never ridden a horse before. B. My friend never rode a horse before. C. My friend has never ridden a horse before. D. My friend had never ridden a horse before. Question 39. Marie/ like/ window shopping/ her close friend/ Saturday evenings. A. Marie likes window shopping with her close friend in Saturday evenings. B. Marie like window shopping with her close friend in Saturday evenings. C. Marie likes window shopping with her close friend on Saturday evenings. D. Marie like window shopping with her close friend on Saturday evenings. Question 40. There/ many/ English/ speaking countries/ the world A. There are many English speaking countries on the world. B. There is many English speaking countries in the world. C. There are many English speaking countries at the world. D. There are many English speaking countries in the world.

Cho tam giác ABC cân tại A, tia phân giác góc A cắt BC tại D. a. Chứng minh DB = DC. b. Kẻ DH vuông góc AB (H thuộc AB), DK vuông góc AC (K thuộc AC). Chứng minh tam giác DHK cân. c. Chứng minh HK // BC.

Hãy viết phương trình propen và propin H2O, xúc tác h+

Choose the correct sentence so that it has a similar to the first one. Question 33: They organized this festival some years ago A. This festival was organized some years ago B. This festival has been organized some years ago C. This festival was organizes some years ago D. This festival was being organized some years ago Question 34. Playing computer games gives him pleasure A. He enjoy playing computer games B. He enjoys playing computer games give him pleasure C. He doesn’t enjoy playing computer games D. He enjoys playing computer games Question 35: Mary was sick, so she could not go to school. A. Although Mary was sick, she could not go to school B. As Mary was sick, she could not go to school C. Because of being sick, Mary could go to school D. Because Mary was sick, so she could not go to school Question 36: I love watching TV in the evening. A. I am interesting in watching TV in the evening B. I am fond of watching TV in the evening C. I am keen in watching TV in the evening D. I am interested in watch TV in the evening Question 37: She is unhealthy because she doesn’t take any exercise. A. If she takes any exercise, she would be healthy B. If she took any exercise, she wouldn’t be healthy C. If she took exercise, she would be unhealthy D. If she took exercise, she would be healthy

Một đội máy cày dự định cày 30 ha trong một ngày. Khi thực hiện đội đã cày mỗi ngày 40 ha nên đã hoàn thành sớm hơn dự định là 2 ngày và vượt mức dự định 10 ha. Tính diện tích ruộng mà đội phải cày theo dự định?