Câu 20: Để 1 động cơ điện hoạt động cần cung cấp một điện năng là 9 kJ. Biết hiệu suất của động cơ là 90%,công có ích của động cơ là : A. 1kJ B. 3kJ C. 8,1kJ D. 81kJ Câu 21: Một động cơ điện trên có ghi 220V- 2200W được mắc vào 2 điểm có U = 220V. Biết hiệu suất của động cơ là H=90%. Điện trở thuần của động cơ điện đó là: A. 2,2Ω B. 22Ω C. 19,8Ω D. 198Ω Câu 22: Để 1 động cơ điện hoạt động cần cung cấp một điện năng là 4321kJ. Biết công có ích của động cơ 3888,9kJ. Hiệu suất của động cơ là: A. 60% B. 70% C. 80% D. 90% Câu 23: Khi dây chì của cầu chì bị đứt, ta phải: A. thay dây chì khác có tiết diện to hơn B. thay dây chì khác có tiết phù hợp C. thay dây chì bằng dây đồng D. thay dây chì bằng dây sắt Câu 24: Những dụng cụ nào dưới đây có tác dụng bảo vệ mạch điện khi sử dụng? A. ampe kế B. vôn kế C. công tắc D. cầu chì các Bạn viêt cách giải giúp mik ạ

Exercise 4: Rewrite the sentences with the word given. 1. Although he has a very important job, he isn’t particularly well-paid. In spite of____________________________________________________ 2. Although I had never seen her before, I recognized her from a photograph. Despite _____________________________________________________ 3. She wasn’t wearing the coat although it was quite cold. In spite of _____________________________________________________ 4. We thought we’d better invite them to the party although we don’t like them very much. Despite _____________________________________________________ 5. Although I didn’t speak the language, I managed to make myself understand. In spite of_____________________________________________________ 6. Although the heat was on, the room wasn’t warm. Despite_____________________________________________________ 7. I didn’t recognize her although I’d met her twice before. In spite of_____________________________________________________ 8. We’re not very good friends although we’ve known each other a long time. Despite_____________________________________________________ 9. Although Minh was ill, he still came to the meeting. In spite of_____________________________________________________ 10. Although he promised that he wouldn’t be late, he didn’t arrive until 9 o’clock. Despite_____________________________________________________

Tìm số các giá trị nguyên của tham số m để phương trình x²+2x-3√(x²+2x+m)+m+2=0 có đúng hai nghiệm phân biệt trên [1;2].

Câu nào cũng đc giải giúp ạ cần gấp nhiều câu cang tốt

Exercise 3: Rewrite the sentences, beginning with the words in parentheses: 1. She has plenty of money, but she is very mean. (although) ______________________________________________________________ 2. They have a car, but they rarely use it. (though) ______________________________________________________________ 3. He was innocent, but he was sent to prison. (although) ______________________________________________________________ 4. He has a number of relatives living nearby, but he never visits them (even though) ______________________________________________________________ 5. She never takes any kind of exercise, but she is quite fit and healthy. (even though) ______________________________________________________________ 6. The keyboard wasn’t working well. She tried to finish the letter (although) ______________________________________________________________ 7. The forecast said it would rain. It turned out to be a beautiful day. (although) ______________________________________________________________ 8. I’m no better. I’ve taken the bill. (even though) ______________________________________________________________ 9. The traffic was bad. I arrived at the airport on time. (though) ______________________________________________________________ 10. I didn’t get the job. I had all necessary qualifications. (though) ______________________________________________________________ 11. We enjoyed the vacation. It rained a lot. (although) ______________________________________________________________ 12. She felt sick. She went to work. (though) ______________________________________________________________ 13. I was really tired. I couldn’t sleep. (even though) ______________________________________________________________ 14. He is very rich. He isn’t happy. (although) ______________________________________________________________ 15. She couldn’t answer the question. She is very intelligent. (though) ______________________________________________________________

Exercise 2: Combine these sentences using: though, although, even though 1. Lion dancing is very popular in Viet Nam. My friend Anny does not enjoy it. ______________________________________________________________ 2. Bob always walks to work. He is living in the city. ______________________________________________________________ 3. My house is near the beach. I rarely go swimming. ______________________________________________________________ 4. My brother is working in Ha Noi. He comes home on every public holiday. ______________________________________________________________ 5. Paul is an Australian, he enjoys Vietnamese New year. ______________________________________________________________ 6 Most children go to see the firework show, Linh and Mai stay home watching TV. ______________________________________________________________ 7. Nick used to smoke. He seems to be in good health. ______________________________________________________________ 8. I couldn’t sleep. I was tired. ______________________________________________________________ 9. Henry’s friend is a millionaire. He hates spending money. ______________________________________________________________ 10. We couldn’t get tickets. We queued for an hour. ______________________________________________________________

Các bạn giải dùm mình nhá mình sắp nộp rồi

15. Although Sue felt tired, she stayed up late talking to Jill. A. Despite feeling tired, Sue stayed up late talking to Jill. B. In spite feeling tired, Sue stayed up late talking to Jill. C. Sue wouldn’t feel tired despite staying up late talking to Jill. D. Sue stayed up late talking to Jill. As a result, she was tired. 16. Even though Trung had a bad cold, he went to the concert. A. In spite of his bad cold, Trung went to the concert. B. Trung had a bad cold because he went to the concert. C. Trung went to the concert despite of having a bad cold. D. Trung had a bad cold. However, he went to the concert. 17. _____it was raining heavily he went out without a raincoat. A. In spite B. In spite of C. However D. Although 18. _____he wasn’t feeling very well; Mr. Graham went to visit his aunt as usual. A. Although B. However C. Therefore D. Still 19. He was offered the job______ his qualifications were poor. A. despite B. in spite of C. even though D. Whereas 19. ______ we were in town, we often met him. A. For B. Although C. So D. When 20. She didn’t get the job ____ she had all the necessary qualifications. A. because B. although C. so D. but 21. I could not eat ____ I was very hungry. A. even though B. in spite C. despite D. in spite the fact that 22. In spite _____, the baseball game was not cancelled. A. the rain B. of the rain C. it was raining D. there was a rain 23. ______ he had enough money, he refused to buy a new car. A. In spite B. In spite of C. Despite D. Although 24. ______, he walked to the station. A. Despite being tired B. Although to be tired C. In spite being tired D. Despite tired 25. The children slept well, despite _____. A. it was noise B. the noise C. of the noise D. noisy 26. She left him __________ she still loved him. A. even if B. even though C. in spite of D. despite 27. _______ her lack of hard work, she was promoted. A. In spite B. Even though C. in spite of D. despite of 28. _______ they are brothers, they do not look like. A. Although B. Even C. Despite D. In spite of

1. _______ he likes chocolate, he tries not to eat it. A. as B .though C. since D. despite 2. _______________ he had enough money, he refused to buy a new car. A. In spite B. In spite of C. Despite D. Although 3. _______________, he walked to the station. A. Despite being tired B. Although to be tired C. In spite being tired D. Despite tired 4. ________________ her lack of hard work, she was promoted. A. Because B. Even though C. In spite of D. Despite of 5. She left him _______________ she still loved him. A. even if B. even though C. in spite of D. despite 6. Last night we came to the show late _______the traffic was terrible. A. although B. despite C. and D. because 7. _______there is a lot of noise in the city, I prefer living there. A. despite B. in spite of C. because of D. though 8. _______ the weather, we went sailing. A. despite B. in spite of C. although D. A and B 9. _______Hudson led early, he lost the race. A. though B. although C. even though D. all are correct 10. In spite of not speaking French, Mike decided to settle in Paris. A. Even though Mike didn’t speak French, but he decided to settle in Paris. B. Mike decided to settle in Paris despite he didn’t speak French. C. Mike decided to settle in Paris though the fact that not speaking French. D. Although Mike didn’t speak French; he decided to settle in Paris. 11. Mr. Ba was late for the meeting though he took a taxi. A. Even though taking a taxi, Mr. Ba was late for the meeting. B. In spite of taking a taxi, but Mr. Ba was late for the meeting. C. Mr. Ba was late for the meeting despite the fact he took a taxi. D. Mr. Ba was late for the meeting although having taken a taxi. 12. We came to the meeting on time though the traffic was heavy. A. Despite the traffic was heavy; we came to the meeting on time. B. In spite of the heavy traffic, we came to the meeting on time. C. Even though the heavy traffic, we came to the meeting on time. D. Although the traffic was heavy, but we came to the meeting on time. 13. Although he took a taxi, Bill still arrived late for the concert. A. Bill arrived late for the concert whether he took a taxi or not. B. Bill arrived late for the concert because of the taxi. C. In spite of taking a taxi, Bill arrived late for the concert. D. Bill took a taxi to the concert, but he couldn’t catch it. 14. Although she is rich, she can’t afford to buy the car. A. She doesn’t have enough money to buy the car she likes. B. Rich as she is, she can’t afford to buy the car. C. The car is too expensive for her to buy. D. She wants to buy the car but it costs a lot.

Một ôtô chuyển động đều với vận tốc 36km/h. Tính công và công suất của lực kéo khi ôtô đi đc 15 phút ?. Biết lực kéo của máy là 1000N