Khi kiểm tra những chi tiết máy vừa mới sản xuất xong, người thợ cơ khí thường hay dùng búa gõ vào những chi tiết máy này? Tại sao họ phải làm như vậy?

một hình tròn có chu vi là 15,7 cm thì đường kính cưa hình tròn đó là

giải pt: 2x^4-9x^3+14x^2-9x+2=0

Đọc giúp mình bản vẽ chi tiết này với ạ ...mình đang cần gấp.. Giải giúp mình mình vote 5 sao kèm cảm ơn ạ

1.Viết các đơn thức sau dưới dạng thu gọn: 2x^2y.( -3x^2y^2).x 2.Cho tam giác ABC (AB < AC), M là trung điểm của BC. Đường trung trực của BC cắt tia phân giác của góc BAC tại điểm P. Vẽ PH và PK lần lượt vuông góc với đường thẳng AB và đường thẳng AC. a) Chứng minh: PB = PC và BH = CK. b) Chứng minh: Ba điểm H, M, K thẳng hàng. c) Gọi O là giao điểm của PA và HK.Chứng minh: OA^2+ OP^2+ OH^2+ OK^2= PA^2

Bạn nghĩ như thế nào khi có 1 cậu bé dành 10 triệu tiền lì xì phát khẩu trang miễn phí để phòng dịch ?

qua đoạn trích số phận con người hãy nêu cảm nhận về nỗi đau mà chiến tranh đã gây ra cho con người (viết 1 đoạn văn NGẮN khoảng 15 dòng)

I. Choose the best answer to complete each of the following sentences. 1. Nowadays people..........hours sitting in front of computers. A. spend B. last C. set D. take 2. I think you should take up swimming _____it is suitable for your health condition. A. so B. because C. although D. but 3. My family enjoys........because we can sell vegetables and flowers .......money. A. garden - to B. gardening - for C. gardening - with D. garden - of 4. If your hobby is greeting card making, you can give your....... to your friends as presents. A. hobby B. money C. greetings D. products 5. My sister’s hobby is sewing, and she can get the sewing patterns from the___magazines. A. fashion B. cooking C. sports D. science 6. My brother doesn’t like ice-skating because he thinks it is________. A. danger B. in danger C. dangerous D. endangered 7. My sister is very keen on swimming, and she goes swimming three ____a week. A. time B. a time C. times D. timings 8. We often read the instructions carefully in order to make______of the things we like best. A. meanings B. models C. copies D. uses 9. You need to be to follow eggshell carving because it may take two weeks to complete one shell. A. careful B. interesting C. fit D. patient 10. If you choose sewing as your hobby, you will________ your own clothes. A. do B. make C. take D. get 11. There are many why it is important to have a hobby. A. answers B. reasons C. details D. facts 12. Will you..........making models in the future? A. pick up B. look for C. take up D. find 13. Do you think that hobby is________ and boring? A. easy B. difficult C. danger D. interesting 14. I love my sister’s paintings because she is very in using colors. A. careless B. care C. creative D. imagine 15. A hobby helps you to connect with people. A. other B. others C. another D. the other 16. I join a photography club, and all members love photos. A. take B. taking C. make D. making 17. What does your father do his free time? A. in B. at C. on D. while 18. I think a hobby will always give you and help you . A. pleased - relax B. pleasure - relaxed C. pleased - relaxing D. pleasure - relax 19. You can share your stamps other collectors a stamp club. A. with - at B. to - at C. with - in D. to - in 20. I think this hobby does not cost you much, and you need is time. A. most B. all of C. some D. all 21. Hoa likes music. She often …………. to music in late evenings. A. listen B. listening C. listens D. to listens 22. I enjoy …………. badminton after school. A. doing B. playing C. seeing D. going 23. Ann has a large …………. of stamps. A. collect B. collection C. collecting D. collections 24. How …………. you go to the library after school? A. often B. much C. many D. usually 25. My sister usually goes to the library with me. She likes___ comic books very much. A. read B. reading C. to read D. reads 26. In big cities, there are many kinds of _____ for young people. A. entertain B. entertains C. entertainment D. entertaining 27. What _____ does Minh like playing in his free time? A. activities B. sports C. things D. subjects 28. He goes swimming when he ______ free time. A. have B. is having C. has D. will have 29. My uncle likes ______ the vegetables we grow ourselves. A. to eat B. eat C. eats D. eating 30. My close friend draws very well. She will be a …………. artist one day. A. fame B. famous C. famously D. famed

giúp mik vs 1. Do you mind if I (ask)…………………… you a private question? 2. Would you mind (close)…………………………… the door, please? 3. The trees are (plant)…………………………… by his father. 4. The new bridge will (build)…………………………… by the end of the year. 5. The garbage can (use)…………………………… to make fertilizer. 6. The boy (read)……………………………… the book is Ba. 7. The old lamp (make)……………………………… in China is five dollars. 8. The window (break)…………………………… last night has been repaired. 9. Do you mind (travel) …………………………… such a long distance to work everyday? 10.Rice and corn(grow)……………….in Vietnam. II. WRITING 1. The boy is playing chess with Ba. He is my father > The man …………………………………………………………………………………………………….. Will you buy me some flowers? > Would you mind…………………………………………….? 3. She went to Ha Noi . She wanted to visit many interesting places > She went to Ha noi in order to…………………………………………………………….…………………. 4.They will build a new school in this area. > A new school……………………………………………………..

Ai giúp mình với! Help me 🙏🙏🙏🙏🙏