Một vật khối lượng 2kg đang chuyển động với vận tốc 25m/s thì trượt lên dốc. Biết dốc dài 50m, đỉnh dốc cao 14m, hệ số ma sát giữa vật và mặt dốc là 0,25. Cho g=10 m/s2. a, Tính công của trọng lực, công của lực ma sát. b, Tính vận tốc của vật ở đỉnh dốc

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B. USE OF ENGLISH Part I. Choose the best option (A, B, C, D) to complete the following sentences (2,0 points) 1. We often go swimming ……………….. Sunday morning. A. in B. on C. at D. for 2. Find the word in which the underlined part is pronounced differently. A. teacher B. reason C. idea D. feature 3. Football is an example of a …………….. sport where you play with several other people. A. team B. individual C. indoor D. dangerous 4. The smallest …………………. in the world is Australia. A. continent B. ocean C. country D. city 5. I’d like to watch motor racing because it is very …………….. A. frightening B. exciting C. excited D. boring 6. Find the word in which the underlined part is pronounced differently. A. clear B. prepare C. ear D. fear 7. Team sports are sometimes called ………………………. sports. A. running B. healthy C. intelligent D. competitive 8. Some developed nations namely Britain, France and Germany are located in …………… A. America B. Asia C. Australia D. Europe Part II. Put the verbs in brackets into the correct forms (1,25 points) 9. Nam (not/ do) …………………………. his homework last week. 10. (you/ watch) …………............................. the tennis match on TV yesterday? 11. Jane (not/be)…………………. at the party last Sunday. 12. I (have)………………………… a wonderful holiday with my family last July. 13. Please (hurry) …..................... up, we are going to be late for school again. Part III. Complete the second sentence so that it has a similar meaning to the first. (0,5 points) 14. Minh plays football very well.  Minh is very good………………………………………………………….. 15. We do a lot of outdoor activities in summer.  We take part in…………………………………………………………..