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minhthaot36
1 năm trước
GIÚP MÌNH VỚI Ạ. Cho hình lăng trụ ABC.A'B'C'. Gọi G là trọng tâm tam giác ABA' và M là điểm tùy ý trên đường thẳng B'C'. Đường thẳng MG cắt mặt phẳng (ABC) tại điểm N. Tính tỉ số GM/GN.
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When people think of water buffalos, they often imagine wild and dangerous animals. But unless they are hurt or angered, water buffaloes are probably the gentlest farm animals in the world. Despite their frightening appearance, they are much like household pets. Unlike cattle, they are quiet and have a natural fondness for humans. Water buffaloes are so patient and mild tempered that there is no need to restain them during milking. Because of the animal’s calm nature, water buffaloes almost never have their horns removed. In contrast, most dairy cattle are dehorned when they are young to prevent them from injuring one another when they mature. Another common myth is that water buffaloes can be raised only near water. Though they love to roll in muddy water, water buffaloes live and reproduce normally in situations where there is not enough water to do this. However, several reseachers report that water buffaloes who wallow in muddy water do not need to be treated with insecticides because the mud coating that forms on their skin protects them from insects and parasites. Another fasle belief about water buffaloes is that they can live only in tropical areas. Actually, buffaloes are able to exist in a wide range of climates. Although they are most common in the tropics, water buffaloes were used to pull snowplows in parts of Europe many years ago. 1. According to the author, water buffaloes are ____ A. usually gentle B. often dangerous C. easily frightened by people D. easily frightened by cattle 2. Where can water buffaloes live? A. only in tropical areas B. in many different places C. only in Europe D. only in places with a lot of water 3. According to the passage, how can rolling in muddy water help water buffaloes? A. It protects them from paraites B. It washes insecticides off them. C. It helps them reproduce. D. It keeps them cool. 4. Why are water buffaloes not dehorned? A. Removing the horns is dangerous to humans. B. They don’t use their horns to attack. C. They don’t grow horns. D. Removing their horns can injure the buffaloes. 5. Which of the following statements best expresses the main idea of this passage? A. Water buffaloes used to be common all around the world. B. Water buffaloes and cattle have many similarities C. Water buffaloes can be dangerous animals. D. Many people have incorrect dieas about water buffaloes.

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