Câu 5. Đốt cháy 18,6g Photpho trong không khí tạo thành điphotpho pentaoxit (P2O5). a. Viết phương trình hóa học. b. Tính thể tích khí oxi cần dùng ở (đktc)? c. Tính thể tích không khí, biết thể tích khí oxi chiếm 20% thể tích không khí? d. Tính khối lượng chất tạo thành? (Cho: O = 16, P = 31, Cl = 35.5, K = 39)

Correct the verbs from to complete the sentences. 1. If you (go) .............. away, please write to me. 2. If he (eat) ............ another cake, he will be sick. 3. I (not do) ........... that if I (be) ..................... you 4. If he (take) ............ my advice, everything can go well 5. He never does homework. If he (do) ....................... his homework, he (not worry) .................... about his exam 6. What you (do) ................. if she (be) refuses your invitation? 7. If today (be) ......................... Sunday, we (go) ................to the beach 8. Unless they ( pass) ................ their examinations, they would join the army 9. You (be)...................... ill if you drink that water 10. If Tom (go) ................. to bed earlier, he would not be so tired 11. If it's raining heavily, we (not go) .................. for a donkey rice 12. If he (try) ...................................... hard , he'll pass the examination 13. I could understand the French teacher if she (speak) ................. more slowly. 14. If I (finish) ............. the work in time, I (go) .................. to the football game. 15. If you (see) ................... Mary today, please (ask) ................... her to call me.

cho hình chữ nhật ABCD có AB bằng 90cm , chiều rộng bằng 2/3 chiều dài . trên BC lấy điểm M bất kì , nối 2 đoạn MA và MD ta được tam giác ADM . tính điện tích tam giác đó

Use the correct tense or form of the verb given in each sentences. (1.5 pts) 25. My pen pal was really ____________________ by the beauty of Ha Long Bay. (impress) 26. Both competitors are ____________________ strong and fast. (surprise) 27. The company has made a new motorbike having very low fuel ____________________. (consume) 28. A large number of car accidents are caused by fast and ____________________ driving. (care) 29. Could You send me details of courses for _____________ who have never learnt English before. (begin) 30. Ba's family and Liz had a very ____________________ day in the countryside last weekend. (enjoy) Rearrange the groups of words in a correct order to make complete sentences (0.5 pt) 31. have lost their lives/ Many people around the world/ natural disasters/ and homes because of/ 32. The survival of/ depends on each and/ the natural world/ every one of us/ Rewrite each of the following sentences in another way so that it means almost the same as the sentence printed before it. (2.0 pts) 33. He can't drive because he's very young He is not _______________________________________________________________________ 34. City life is not as peaceful as country life. Country ________________________________________________________________________ 35. It's not safe for kids to go hunting Pokemon on the street Going hunting ________________________________________________________________ 36. The boy hasn't visited his grandparents for two months. The boy last __________________________________________________________________ Choose the word whose underlined part is pronounced differently from that of the others. 37. A. trip​​B. river​​C. life​​​D. city 38. A. rested​​B. hiked​​C. dressed​​D. advanced Choose the word that has the different stress. 39. A. city​​B. poem ​​C. advice ​​D. chidren 40. A. uniform ​B. assistant​​C. collection​​D. professor

. Choose the word (A, B, C or D) that best fits the blank space in the following passage. (1,5pts) In many Western countries, people (19) ……. Halloween on October 31. The word Halloween (20) …….. from All Hallows- Eve". It is the night before All Saints- Day, a religious holiday in some parts of the world. On this night, children dress up in special costumes, put (21) …………….. masks , and go door to door saying -trick-or-treat" to get candy. Many people decorate their homes with paper ghosts, black cats or witches to give their houses a (22) …………….. look. People also decorate their homes with jack-o-lanterns. They carve scary faces on pumpkins, and (23) ……….. candles inside the pumpkins. In some places, both children and adults can make (24) ……. of haunted houses. They all seem very excited about the festival. 19. A. celebrate​​B. reduce​​​C. save​​​D. exchange 20. A. gets​​​B. goes​​​​C. comes​​D. reaches. 21. A. in​​​B. off​​​​C. out​​​D. on 22. A. bored​​B. relaxed​​​C. careful​​D. scary 23. A. light​​​B. to light​​​C. lighting​​D. lighted 24. A. parts​​B. tours​​​C. turns​​D. prizes

Modal will to make request, offers and promises 1. Can you open the window please?  A. No, I won't mind. B. Yes I will. C. Sure. 2.  Could you help me? A. Yes I will. B. What seems to be the problem? C. Peter is not around. 3. Would you mind waiting a little bit? A. Yes, I'll wait. B. No.  C. Of course. 4. Could you fax this paper for me?  A. Sure. Who's faxing it? B. Sure. Where's the fax machine? C. Sure. How much is it? 5. Don't ever be late again. A. I will. B. I won't. C. Yes, sure.

đặt tính rồi tính : 266,22:34=.......... các bạn giải thích rõ gúp mình với i'm thanks

Theo em xe ô tô và xe máy khi chạy cùng quãng đường thì nhiệt độ xe nào cao hơn? Vậy chất làm mát ô tô và xe máy có giống nhau không?

Read the following letter. Decide if the statements from 13 to 16 are True or False and choose the correct answer (A, B, C or D) for the questions 17 and 18. Today almost everyone walking down the street has at least one mobile phone in their pocket. That is because many mobile phones are upgraded every year around the world; and most people are interested in changing their old mobile phone for a new one. There has been an estimated number of 90 million unwanted mobile phones in the UK alone! This mountain weighs around 12.000 tonnes, but only about 5°a of it is recycled. What makes us worried most is that mobile phones contain harmful chemicals which are released into the environment when phones begin to degrade and, in addition, large amounts of carbon dioxide are also produced during the manufacture of phones. It seems that the more modern mobile phones become, the worse our environment gets. 13. Mobile phones are modernized every year around the world. 14. Most people are keen on having a newer mobile phone. 15. About half of unwanted mobile phones in the UK are recycled. 16. Old mobile phones do no harm to the environment. 17. What is the passage mainly about? A. The modernization of mobile phones is necessary. B. There are more and more mobile phones in the world. C. The modernization of mobile phones make the environment worse. D. The manufacture of phones produces carbon dioxide. 18. Which of the following can be inferred from the passage? A. Modern mobile phones are worse for the environment than the older ones. B. Mobile phones are getting cheaper and more modern. C. People in the UK are very concerned to recycle old mobile phones. D. Used mobile phones can pollute the environment.

tính lim khi x->1^+,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,