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Trước đây CFC được sử dụng làm chất sinh hàn trong các thiết bị làm lạnh, nhưng hiện nay chất này đã bị cấm do gây phá huỷ tầng ozon. CFC là các chất nào ? A. CF4 và CCl4 B. CCl4 và CFCl3 C. CF2Cl2 và CFCl3 D. CF4 và CF2Cl2
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1. Fill in the blank with a word/ phrase in the box. Titanic is a 1997 American epic (1) disaster film directed, written, co-produced, and co-edited by James Cameron. A (2) account of the sinking of the RMS Titanic, it (3) Leonardo DiCaprio and Kate Winslet as members of different social classes who fall in love aboard the ship during its ill-fated maiden (4) . Cameron's inspiration for the film came from his fascination with shipwrecks; he felt a love story interspersed with the human loss would be (5) to convey the emotional impact of the disaster. Production began in 1995, when Cameron shot footage of the actual Titanic wreck. The modern scenes on the research vessel were (6) on board the Akademik Mstislav Keldysh, which Cameron had used as a base when filming the wreck. Scale models, computer-generated (7) , and a reconstruction of the Titanic built at Playas de Rosarito in Baja California were (8) re-create the sinking. The film was partially funded by Paramount Pictures and 20th Century Fox. It was the most expensive film made at that time, with an estimated budget of $200 million giúp với

điền giới từ a/an/the hoặc x 1. There was . . . knock on . . . door. I opened it and found . . . small dark man in . . . blue overcoat and . . . woollen cap. 2. He said he was . . . employee of . . . gas company and had come to read . . . meter. 3. But I had . . . suspicion that he wasn't speaking . . . truth because . . . meter readers usually wear . . . peaked caps. 4. However, I took him to . . . meter, which is in . . . dark corner under . . . stairs (. . . meters are usually in . . . dark corners under . . . stairs). 5. I asked if he had . . . torch; he said he disliked torches and always read . . . meters by . . . light of . . . match. 6. I remarked that if there was . . . leak in . . . gaspipe there might be . . . explosion while he was reading . . . meter. 7. He said, 'As . . . matter of . . . fact, there was . . . explosion in . . . last house I visited; and Mr Smith, . . . owner of . . . house, was burnt in . . . face.' 8. 'Mr Smith was holding . . . lighted match at . . . time of . . . explosion.' 9. To prevent . . . possible repetition of this accident, I lent him . . . torch. 10. He switched on . . . torch, read . . . meter and wrote . . . reading down on . . . back of . . . envelope. 11. I said in . . . surprise that . . . meter readers usually put . . . readings down in . . . book. 12. He said that he had had . . . book but that it had been burnt in . . . fire in . . . Mr Smith's house. 13. By this time I had come to . . . conclusion that he wasn't . . . genuine meter reader; and . . . moment he left . . . house I rang . . . police.

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