Người ta xây bể nước dạng hình hộp chữ nhật có CD=3m,CR=2m,C.cao=1,2m a)Người ta lát gạch xung quanh và đáy bể .Tính S lát gạch . b)Người ta mở vòi cho nước chảy vào bể ,trung bình mỡi giờ vòi chảy được 1,5m khối nước .Hỏi sao bao lâu vời chảyb đầy bể?

Các câu hỏi liên quan

Write a paragraph about the topic: “Is television a blessing or a curse?”, using the cues given. IS TELEVISION A BLESSING OR A CURSE? 1. Human beings / gained much specific advancement recently. There / be a series of inventions that / have brought human conveniences / a modern life. 2. Television / set as a good example that certainly influences / our life in communication and entertainment. However, TV also / cause some bad effects of time-consuming / health problems. 3. In the first place, television / help people in the ways of communicating / each other and entertaining their life. Thanks / the appearance TV, people can keep / with up-to-date / the world. 4. What our / be if we do not have a TV at home. Because TV is a cheap / available tool / provide us daily information. 5. Also, watching TV is a valuable kind of entertainment that / help people relax after working hard or suffering / a busy life. Last but not least, TV has changed husband's behavior in connecting / each other. 6. Beside of good advantages of TV, watching TV may cause some disorders in health / working time / well. 7. Some people spend long hours in / of a TV set, they may neglect then work or duty in taking care / their family members. And young people may work less effectively / addicted to watching TV lead to passiveness and laziness. 8. In conclusion, everything / have two sides and TV is optional. It is obvious that TV / benefit our life in making people become friendly and close. I totally agree that TV is a great invention and we / have to be aware / its good points by using it suitably.