玉米和辣椒都是普通的食物，然而人们发现它们有很多不凡之处。且不谈其各种营养对人们的益处，单是它们所含的食用色素就吸引了全世界很多科研人员的注意。在玉米中，有黄色素；在辣椒中，有红色素，这两种食用色素，可广泛应用于人造奶油，糖果、糕点等食品的着色。
这段话主要谈论的是( )。
A．玉米和辣椒对人体的益处
B．玉米和辣椒的不凡之处在科研领域的应用
C．玉米和辣椒的营养价值与吸引力
D．玉米和辣椒所含的食用色素及其应用价值
参考答案：D
解析： 文段中“单是它们所含的食用色素就吸引了全世界很多科研人员的注意”、“在玉米中，有黄色素”、“在辣椒中，有红色素”，从而可以看出该段主要谈论的是“玉米和辣椒所含的食用色素”，D选项正确。
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| Mr. Johnson worked in a restaurant, but he wasn't a good 1 and at last he was sent away. Once he went to see the doctor because something was wrong with his ear. He 2 the doctor twenty dollars after the 3 treatment. It made him think it easy to get money as a doctor. So later he 4 a hospital in a small town. At first, people there knew 5 about him and they came to see him. But soon they found he couldn't treat them at all and his medicine didn't 6 . One evening he heard the door 7 at and found a traveler 8 in front of his hospital. He thought he had a bad cold and 9 him take some medicine. After that the man left. On the second day a young man came in and said, "Thank you very much, doctor!" It 10 Mr. Johnson as he hadn't seen him before. The young man continued, "My uncle died from your wrong treatment yesterday and he left much money to me!" | ||||
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