Hiđrocacbon B có thành phần gồm 82,76%C, phần còn lại là H. a. Hãy lập CTPT của B, biết dB/O2= 1,8125? b. Viết các CTCT có thể có của B?

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V.Put the correct form of verbs: 1.Mai (visit)_______________________ Nha Trang last summer. 2. You should (wash)_________________ your hands before meals. 3. Lan (visit)________________________Nha Rong Harbor next week. 4. They (play)__________________________ soccer in the school yard at the moment. 5.Nam (not be)_________ very sporty. He never (take)__________part in after school activities . 6.Be quiet! The baby (sleep)________________. You shouldn’t (make)___________ noise. 7. We (have)___________________ a day off next week. 8. Where (be)__________ your father now?- He (work)_______________________in the gadern. 9. Next week, I (see) __________________a movie. Let’s (go) ________________with us. 10. He can (speak)_________________ English well. 11.We (not go)__________________ to the movies so often. 12.Tomorrow is Sunday. What______you (do)_____________? - I (stay)_________________ at home . 13. The members of the stamp collector’s club (meet)_________________ at the library next Friday. 14.I’d like (see)_________________a movie tonight. 15.You should (relax)_____________________. 16. Hoa often (play)________________badminton in her free time. 17. Lan(watch)_________________TV at the moment. 18. Nam (not practice)___________________the piano every day. 19.She (be)_____________________ free tomorrow. 20. We (listen)__________________________ to music right now. 21. They (not watch) _______________________ TV last night. 22. Mai (meet) _________________ her grandparents every week. 23. He (travel) _______________________ Nha Trang next summer. 24. What about (go) ______________________ to the movies? 25. They (watch) ____________ _____the black and white programs thirty years ago. 26. Mr Tan always (go) ________________ to school on foot. 27. Let’s (come) _____________________ to my house for dinner. 28. She mustn’t (go)___________________ out late at night. 29.How about (play)___________________ chess? 30. He (be)_______________ in Da Lat last month. 31.She (not learn)___________________ English when she was young. 32. Would you like (have)______________ dinner at my house tonight? 33. What _______ she (do)________ last night?- She (listen)_____________ to music. 34. He (play)_________________ soccer every afternoon. 35. Be careful! The bus (come)______________________. 36. Nam likes (play)___________________ sports. 37. We (have) _______________________ a course of English next month. 38. I (buy) ________________ a new comic yesterday. 39. Nam and Hoa (wait) _______________________ for their parents at the moment. 40.What time __________ you (go) __________to bed last night?- I(go)__________ to bed at 9. 41. She never ( stay)________________ up late at night. 42. My mother ( not plant)_________________flowers in the garden at this time. 43. I (play) _______________________ soccer with my friends tomorrow. 44.We (not watch) ____________________ a good movie on TV last night. 45. Hoa (meet) __________________ her friends every day. 46. Yesterday, I (help) _________________ my mother with the homework. 47. Lan (visit)_________________ Nha Rong Harbor next week. 48. They (play)_____________________ soccer in the school yard at the moment. 49. Hoa (brush)___________________ her teeth every day. 50. Last week, the dentist (fill)_____________ a cavity in Minh’s tooth. 51. You must (do)__________ your homework before going to the bed. 52. Would you like (have)_____________ dinner at my house tonight? 53. Nam (not be)_______________ at home last night, he (go)_________ out with his friends. 54. My uncle (raise)__________________ a lot of chickens at the moment. 55. Ba and Tuan often (play)____________ chess in their free time. 56. She will be 14 on her next birthday. She (invite)_____________ her classmates to her party. 57.We must (do)___________ our homework before going out. 58. Hoa and her aunt (buy)________________ spinach, oranges and beef yesterday. 59. Nam usually (play)_________________ catch at recess.

Câu: 1 Trung và Nam Mĩ có bao nhiêu đới khí hậu? * 5 điểm A. 3 B. 4 C. 5 D. 6 Câu 2: Đặc điểm địa hình của eo đất Trung Mĩ:  * 5 điểm A. Núi và cao nguyên chiếm diện tích lớn B. Có nhiều núi lửa C. Đồng bằng ven biển nhỏ hẹp D. Cả A, B, C đều đúng Câu 3: Đồng bằng ở trung tâm Nam Mĩ là đồng bằng nào?                                       * 5 điểm A. Pam-pa B. A-ma-dôn C. La-pla-ta D. Ô-ri-nô-cô Câu 4: Quan sát hình 41.1 (SGK) cho biết ở Nam Mĩ các sơn nguyên nào có nhiều tài nguyên khoáng sản?  * 5 điểm A. Sơn nguyên Guy-a-na B. Sơn nguyên Bra-xin C. Cả A, B đều đúng D. Cả A, B đều sai Câu 5: Hệ thống núi An-đét có độ cao trung bình:                       * 5 điểm A. 1000-2000m B. 2000-3000m C. 3000-5000m D. 5000-6000m Câu 6 :Trung và Nam Mĩ kéo dài từ phía bắc của chí tuyến Bắc đến 53054’N nên có đủ các đới khí hậu:         * 5 điểm A. Xích đạo, nhiệt đới, cận nhiệt đới, ôn đới. B. Xích đạo, nhiệt đới, cận cực, hàn đới. C. Xích đạo, nhiệt đới, cận nhiệt đới, cực đới. D. Xích đạo, cận nhiệt đối, ôn đới, cực đới. Câu 7: Đâu không phải nguyên nhân khiến phía Tây Nam Mĩ khô hạn là:     * 5 điểm A. Núi cao. B. Ngược hướng gió. C. Dòng biển lạnh. D. Khí hậu nóng, ẩm.