6.you must see the headmaster =>You've .... 7.why isn't this TV working? =>What....... 8.when is John and Mary's wedding? =>When are.... 9.most people can understand him when he speaks English? =>He can make...... 10.we can't afford to buy this car =>The car

Bài 12: Chứng tỏ 1/ (a – b + c) – (a + c) = - b 2/ (a + b) – (b – a) + c = 2a + c 3/ - (a + b – c) + (a – b – c) = - 2b 4/ a(b + c) – a(b + d) = a(c – d) 5/ a(b – c) + a(d + c) = a(b + d)

Nhận biết bằng pphh: a) NaCl, NaBr, NaI, HCl, H2SO4, NaOH b) NH4Cl, FeCl3, MgCl2, AlCl3 c) Chỉ dùng quỳ tím: Na2SO4, NaOH, HCl, Ba(OH)2

Một cái hộp có dạng hình hợp chủ nhật có diện tích xung quanh là 70 đời xi mét vuông chiều dài chiều cao 4 đề xi mét chiều rộng bằng 2 / 3 chiều dài tính a)Tính chiều dài chiều rộng cái hộp đó b)thể tích cái hộp đó Làm ơn giúp tui với tui sẽ cho các bạn 5 sao

Giải giúp mình với nha. Mình cảm ơn!!

tìm m để phương trình: mx-5=4x có nghiệm

Fill in the blank with a word/ phrase in the box. Trains,discourage,transport,expensive, example ,problem,cities,pollution Traffic congestion in many (1) around the world is severe. One possible solution to this (2) is to impose heavy taxes on car drivers and use this money to make public transport better. One of the first benefits of such a measure is that the heavy taxes would (3) car owners from using their cars because it would become very (4) to drive. This would mean that they would begin to make use of public (5) instead, thus reducing traffic problems and (6) as well. Another benefit would be that much more use would be made of public transport if it was improved. It is often the case that public transport in cities is very poor. For (7) , we often see old buses and (8) that people would rather not use. High taxes would generate enough money to make the necessary changes.

Bài 9:Tìm x: c)53,2:(x-3,5)+45,8=99

IV. Choose the best answer 1. The students are having a ________ check –up. A.scales B.measure C. medical D. measuring 2. I would like ________ some fruit and vegetables. A.buying B.to buy C.buy D. buys 3. You ought _________ to the dentist. A.to go B.go C. going D. goes 4. This river is very ________ for the swimmers. A.danger B.dangerous C. dangerously D. dangerly 5. Walking is a good sports___________ . A.game B.health C. activity D. action 6. I _______ stay in bed because I have a bad cold. A.must B.can C. shouldn’t D. mustn’t 7. _______________?– I’d love to . A. Do you like to go swimming ? B. Would you like to go swimming ? C.What about swimming ? D. Let’s go swimming? 8. Teenagers like_______________the latest pop music. A.hearing B.hear C. to hear D. for hearing 9. We don’t have a TV__________ our place. A.in B.on C. at D. for 10. I am going to the_________ center. A.amuse B.amusing C. amusement D. amused 11. He has plenty of homework ____________ tonight. A.to do B.do C. doing D. for doing 12. Nam often __________ an hour a day playing video games. A.takes B.has C. spends D. gets 13. They __________ to visit their old friends tomorrow. A.will B.are going C. will be D. are 14.Hoa __________ the busy city traffic now. A.used to B.uses to C. gets used to D. will used to 15.The students have a ___________ break between for periods. A.five - minutes B.five minutes C. five - minute D. five minute 16. She goes to the public library___________. A.carefully B.regularly C. suddenly D. fluently 17. There is a good movie __________ at Thang Long theater. A.on B.in C.at D. with 18. Are you interested__________ pop music? A.on B.in C.at D. with 19. I have a___________ summer vacation each year. A.three- months B.three months C. three- month D. three month 20. My mother added__________ soy sauce to the spinach. A.many B.a few C. a little D. much 21. I don’t want much sugar. Just ___________, please! A.many B.a few C. a little D. a lot 22. Students have two_________ each day. A.20- minute breaks B. 20- minutes breaks C. 20- minutes break D. 20- minute break 23. What’s __________ TV tonight? A.on B.in C.at D. with 24. We will_____________ our old friend next week. A.meets B.meet C.met D. meeting 25. He often ___________ his teeth after meals. A.brush B.brushs C.brushes D. to brush 26. You musn’t __________ out late. A.go B.to go C.going D. goes 27. I received a letter _________ my friend. A.on B.in C.at D. from 28. Minh is scared _________ seeing the dentist. A.on B.in C.of D. with 29. _________ don’t you come to my house? A.Why B.What C.When D. How 30. My new school is different_________ my old school. A.on B.from C.at D. with 31. We know the the food we eat __________ our whole life. A.allows B.affects C.makes D. touches 32.She didn’t_________ TV last night. A.watches B.watched C.watch D. watching 33. Today , many families have a TV_______. A.set B.neighbor C.programs D. together 34. I have a __________. So, I must go to the dentist. A.stomachache B.headache C.toothache D. cold 35.There was a wide_________ of fruit on display. A.selection B.select C.selected D. selecting 36. Did you buy any souvenirs in Nha Trang? – Yes, I_______. A.do B.does C.did D. doing 37. I prefer going out to__________ at home on the weekend. A.stay B.stays C.stayed D. staying 38. __________didn’t she come to school yesterday?- Because She was sick. A. Why B. How C. What D. When 39. When I have a toothache, I will come to see a ___________. A.doctor B.teacher C.dentist D.nurse 40. She ____________ to Nha Trang last summer. A.went B.goes C.is going D.will go 41. What______________ you do yesterday? A. do B. did C. will D. Were 42. You have to take care_________ yourself when you’re away home. A. in B. on C. at D. of 43.What’s your__________, Lan? – I’m 45kilos. A. weight B. height C. age D. name 44. Yesterday, I ___________ to school because I was sick. A. don’t go B. go C. went D. didn’t go 45. Ha likes bananas and_________ do we. A. so B. too C. either D. neither 46. They prefer reading___________ watching TV. A. in B. to C.than D.more than 47. Messi plays soccer_________. A.skill B.skillful C.skillfully D.good 48. Would you like__________ dinner with my family? A.to have B.having C.has D.have 49. Students should take part___________ outdoor activities. A. at B. on C. in D. for 50. You must be careful. Video games can be____________. A. interesting B. happy C. boring D. addictive

Hai lớp 9A và 9B cùng tham gia vệ sinh sân trường thì công việc được hoàn thành sau 1 giờ 20 phút. Nếu mỗi lớp chia nhau làm nửa công việc thì thời gian hoàn tất là 3 giờ. Hỏi nếu mỗi lớp làm một mình thì phải mất bao nhiêu thời gian.