Cho phương trình: x2 + 2(m – 1)x – (m + 1) = 0. B, Tìm m để phương trình có 1 nghiệm bằng 1. Tìm nghiệm còn lại D, Tìm m để phương trình có hai nghiệm x1, x2 sao cho x1 = 2x2

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Question III: Read the passage below and choose the best answer (A, B, C or D) to each question Gelatin is a protein substance that comes from the skins and bones of animals. Most people know it as the substance used to make a jellylike salad or dessert. Not only is it useful in making these foods, but it is also beneficial to the consumer because of its high protein content. Gelatin is also commonly used in the photographic industry and in making medicinal capsules. The process for producing gelatin is a long and complex one. In the processing of gelatin made from bones (which varies slightly from that of gelatin made from skin), the grease first must be eliminated. Then the bones are soaked in a solution of hydrochloric acid in order to rid them of minerals and washed several times in water. Next, the bones are placed in distilled water, heated to over 900F for a few hours, placed in fresh distilled water, and then heated again at a little over 1000F. A fluid forms from this heating, and it is concentrated, chilled, and sliced. Finally, it is dried and ground. In its final form, gelatin is white, tasteless, and odorless. 66. It can be inferred from this reading passage that_________. A. fat acids in making good gelatin B. one could easily make gelatin at home C. it is necessary to add minerals to the gelatin D. gelatin is useful for elderly and ill people because it is easy to chew and high in protein 67. The word 'that' in line 6 refers to _________. A. skin B. gelatin C. processing D. bones 68. All of the following industries are mentioned as using gelatin EXCEPT_________. A. the food industry B. the lawn care industry C. the pharmaceutical industry D. the photographic industry 69. According to the passage, why is eating gelatin healthy? A. It is protein rich. B. It is low fat. C. It doesn't damage the teeth. D. It doesn't harm to animals. 70. Which of the following would be best title for this passage? A. Uses for bones B. Protein Foods C. A great Dessert D. The Process of Making Gelatin