C2Viết đoạn văn 5 đến 7 câu giới thiệu về ca huế trên sông hương

Chứng minh hằng đẳng thức :)))) $\frac{ √ a}{ √ a - √ b}$ - $\frac{ √ b}{ √ a+ √ b }$ - $\frac{2b}{a-b}$ =1

Giải giúp m bài này ạ xin chân thành cảm ơn

trình bày các nguyên nhân gây ra tai nạn điện? gia đình em đã thực hiện những biện pháp gì để dẩm bảo an toàn điện

Giúp em câu này vs ak Em hứa sẽ vote sao đầy đủ, em cảm ơn

Từ 1 điểm A trên tia phân giác của góc nhọn Xoy, kẻ AH vuông góc với cạnh Ox (H thuộc Ox) đường thẳng này cắt cạnh Oy tại B So sánh AB với AH

Viết một đoạn văn về đề tài biển đảo quê hương (từ 5 - 7 câu). Chỉ ra những lỗi sai về chủ ngữ và vị ngữ trong đoạn văn em vừa chép.

Quãng đường Ab dài 100m . Trên bản đồ có tỉ lệ 1:10000, quãng đường AB là

giúp mình phần b và c được không hứa vote đầy đủ

2: Read the following passage and choose the best answer. Not so many years ago, the world vitamin was known only to a few scientists. Today it is very widely used, and the importance of vitamins in our foods is common knowledge. Vitamins are life-giving substances found in foods and are needed for the proper growth and general health of the body. The different kinds of vitamins are indicated by letters of the alphabet. At the present time, vitamins A, B1, B2, C, D, E and G are know. A proper diet should contain a collection of foods in which all of these vitamins are present. Vitamins are also prepared and sold in tablet and capsule form. Each vitamin has its particular work to do in the life-giving process. Vitamin B1, for example, benefits appetite and digestion. It also helps the body grow. Another vitamin helps the blood to clot, so that danger of bleeding to death in case of injury is lessened. Still another makes the eyes stronger of seeing at night. Airplane pilots need plenty of this vitamin. Scientists think vitamins may have some effect on keeping the hair from turning gray. 1. Which of the following is not directly stated in the article but is a reasonable conclusion from the reading matter? A. scientists have known about vitamins for centuries. C. vitamins are medicines given to cure diseases. B. to get all the vitamins a person must eat a variety of foods. D. a few people know the value of vitamins. 2. This article as a whole is about_________. A. diet in relation to health C. what vitamins are and what they do B. prevention of diseases D. how scientists discovered vitamins 3. We know the name of vitamins through ___________. A. the pictures B. the food C. the letters of the alphabet D. the different tastes 4. The word "another" in the last paragraph refers to which of the following? A. vitamin B. food C. diet D. medicine 5. Which sentence is NOT true? A. vitamins can be taken only by eating the foods in which they are found B. vitamins can be prepared in tablet and capsule form C. vitamins have an important effect on health. D. each vitamin has its particular work to do.