A là hợp chất của cacbon và hidro trong đó hidro chiếm 20% về khối lượng a/ Tìm CTHH của A biết 1g A ở đktc có thể tích là 746,67ml b/ Trong 0,5 mol A có bao nhiêu nguyên tử cacbon c/ Muốn có 9.10^22 nguyên tử hidro cần lấy mấy gam A

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1. If you plant seeds on the ground, you will have a beautiful garden of flowers → 2. If it snows, we will have to reschedule tomorrow. → 3. If you treat people around you well, you will feel happy in your heart. → 4. If you try to nurture your dream, you will accomplish it in the future. → 5. If it rains, we will have to cancel the concert today. → 6. If you love someone sincerely, you will receive that love again. → 7. If she has a headache, she will see a doctor for treatment. → 8. If you agree to join my birthday party, I will feel very happy. → 9. If he refused the confession, she would feel very sad. → 10. If I successfully complete the project, I will receive a great bonus from the company. → 11. If she tries to cross this mountain, she will win the competition. → 12. If I didn’t skip meals, I wouldn’t feel hungry like this. → 13. If Jack had invested his business, he would have made a big profit from it. → 14. If Irene didn’t ruin the script yesterday, she would have had a chance to memorize it all → 15. If Kate is a rich child, she will travel all over the world. → 16. If she left the current company, it would be difficult for her to find such a good company. → 17. If he had listened to me explain, he wouldn’t have ruined this new computer software. → 18. If I have a chance to go back to the past, I will do the right and meaningful things. → 19. If Mary gave in to the argument, she would have left a good impression on her boss’ heart. → 20. If you believe in success, then you will have a chance to achieve it in the future. -→ 21. If he loved me, he wouldn’t leave me to live in New York. → 22. If she hates me, she won’t help me complete this project. → 23. If Lisa studied hard for the exam, she would not fail. → 24. If I were a bird, I would have flown to the lands I like. → 25. If you were me, you wouldn’t be able to stand this pain. → 26. If your boyfriend is a good person, he will not hit you in arguments. → 27. If you didn’t just teach me the secret to the competition, I wouldn’t be the champion. → 28. If Jane is passionate about the job, she will not find it difficult to do it. → 29. If he is healthy, he can carry this table out. → 30. If you hadn’t been my motivation, I wouldn’t have been able to overcome this terrible disease. →

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I. Earth is the only place we know of in the universe that can support human life. (66) .... human activities are making the planet less fit to live on. As the western world (67) ..... on consuming two-thirds of the world's resources while half of the world's population do so just to stay alive we are rapidly destroying the (68) ..... resource we have by which all people can survive and prosper. Everywhere fertile soil is (69) ...... built on or washed into the sea. Renewable resources are exploited so much that they will never be able to recover (70) completely. We discharge pollutants into the atmosphere without any thought of the consequences. As a (71) ...... the planet's ability to support people is being reduced at the very time when rising human numbers and consumption are (72) ...... increasingly heavy demands on it. The Earth's (73) ....... resources are there for us to use. We need food, water, air, energy, medicines, warmth, shelter and minerals to (74) ...... us fed, comfortable, healthy and active. If we are sensible in how we use the resources, they will (75) ...... indefinitely. But if we use them wastefully and excessively, they will soon run out and everyone will suffer. 66: A. Although B. Yet C. Still D. Despite 67: A. continues B. repeats C. follows D.carries 68: A. individual B. alone C. very D. solitary 69: A. neither B. sooner C. rather D. either 70: A. utterly B. completely C. quite D. greatly 71: A. result B. reaction C. development D. product 72: A. making B. doing C. having D. taking 73: A. living B. real C. natural D. genuine 74: A. maintain B. stay C. hold D. keep 75: A. remain B. go C. last D. stand III. Each nation has many good people who take care of others. For example, some high school and college students in the United States often spend many hours as volunteers in hospitals, orphanages or homes for the aged. They read books to the people in these places, or they just visit them, play games with them or listen to their problems. Other young volunteers work in the homes of people who are sick or old. They clean up their houses, do their shopping or mow their lawns. For boys who no longer have fathers, there is an organization called Big Brothers. College students and other men take these boys to baseball games or on fishing trips and help them to get to know things that boys usually learn from their fathers. Some high school students take part in helping disadvantaged or handicapped children. They give care and comfort to them and help them to overcome their difficulties. Young college and university students participate in helping the people who have suffered badly in wars or natural disasters. During summer vacations, they volunteer to work in remote mountainous areas to provide education for children. Each city has a number of clubs where boys and girls can go to play games or learn craft. Some of these clubs show movies or organize short trips to interest. Most of these clubs use a lot of high school and college students as volunteers because they are young enough to remember the problems of younger boys and girls. Volunteers believe that some of the happier people in the world are those who help to bring happiness to others. 76. Volunteers usually help those who are sick or old in their homes by . A. moving the lawns, doing shopping and cleaning up their houses B. telling them stories, and singing and dancing for them C. cooking, sewing or washing their clothes D. taking them to the baseball games 77. Big Brother is . A. the name of a club B. a home for children who have no brothers C. the name of a team D. an organization for boys who no longer have fathers 78. Most of the boys’ and girls’ club use many high school and college students as volunteers because____. A. they have a lot of free time B. they can understand the problems of younger boys and girls C. they know how to the work D. they are good at playing games and learning crafts 79. Volunteers believe that . A. in order to make others happy, they have got to be happy B. the happiest people in the world are those who make themselves happy C. the happiest people in the world are those who are young and healthy D. bringing happiness to others makes them the happiest people in the world 80. What is the best title for the passage? A. Taking care of others B. Volunteers: the happiest people in the world C. Voluntary work in the United States D. Helping old and sick people in the United States