Số nghịch đảo của một số nguyên a khác 0 là : a . -a b. a c. 1/a d. -1/a

People usually sing because they like music or because they feel happy. They express their happiness by singing. When a bird sing, however, its song usually means much more than that the bird is happy. Birds have many reasons for singing. They sing to give information. Their songs are their language. The most beautiful songs are sung by male (cock) birds. They sing when they want to attract a female (hen) bird. It is their way of saying that they are looking for a wife. Birds also sing to tell other birds to keep away. To a bird, his tree or even a branch of tree, is his home. He does not want strangers to come near him, so he sings to warn them. If a bird cannot sing well, he usually has some other means of giving important information. Some birds dance, spread out their tails or make other sings. One bird has a most unusual way of finding a wife. It builds a small garden of shells and flowers. 21. Why do people usually sing ? A. They like birds. B. They feel happy. C. They want to tell a story . D. They like studying music. 22. Which birds sing the most beautiful songs ? A. Birds in a good temper. B. Cock birds. C. Hen birds. D. Female birds which attract male birds. 23. What warnings does a bird sometimes sing ? A. A warning to keep away. B. A warning to come quickly. C. A warning about the approach of people D. A warning to stop singing. 24. What do most birds usually do if they cannot sing well ? A. warn other birds to go away. B. give their information in another way. C. find a wife. D. fly high in the sky. 25. What is one bird's unusual way of attracting a hen bird ? A. It dances. B. It spreads out its tail. C. It searches for a wife. D. It uses shells and flowers to make a garden.

Chứng minh ∆MOB là tâm giác đều

Giúp mik vs trả lời đúng hết mik cho câu trả lời hay nhất nhé ❤

Tìm x biết: a) √7-x = 2 b) √x-3 > 3

1.The animal is a rhino.It has one or two horns on its snout →The animal 2.The story is too boring for me to remember. →If 3.I said,"If were you,I would concentrate on studying English,Nam" →I advised 4.In spite of his age,Mr.Benson runs 8 miles before breakfast →Althought 5.They think the owner of the house is abroad → The owner

viết bài văn phân tích diễn biến tâm trạng của nhân vật ông hai khi nghe tin làng theo giặc

điền vào chỗ trống ,,many ,much ,few little '' We don't have chickens There are a fruit trees in our garden Does your father grow fruit trees ? She doesn't drink lemonade Minh eatts a eggs every day

Lối phụ họa 1.The students won't accept the dean's decision,and the faculty ....either 2.Your class hasn't begun yet,and neither ...mine 3.The couldn't attend the lecture ,and hết sister ...either 4.He didn't know the answer,and neither ...i

Although coal is the most polluting of fossil fuels, it is still the largest sources of energy worldwide. -> Despite... * mình làm như thế này Despite being the most polluting of fossil fuels, coal is still the largest sources of energy worldwide. nhưng cô lại sửa ntn: Despite being the most polluting of fossil fuels, It is still the largest sources of energy worldwide. Although they spent a huge amount of money on the film, they were unsuccessful. mình làm như thế này:In spite of spending a huge amount of money on the film, they were unsuccessful. nhưng cô lại sửa ntn:In spite of spending a huge of amount of money on the film, they were un successful.