阅读理解。 Hello, everyone. I am the most popular thing in 2009 and 2010. People often fall ill because of me. However, it is largely their own fault (过错) . A tired person may get caught when he goes to the crowded places with polluted air. An unexpected change of the weather can also make me catch them. In hot summer, people turn on the air conditioner (空调) when they return home. They will catch a cold easily. My last victim is an energetic student. After school, he played football for about two hours. Though tired, he still went to the cinema. Then he got back home and took a cold shower right away. I found him easily then. He kept sneezing and his nose was running. Although he put on some warm clothes, it didn't work. The next day, he couldn't go to school. He had lost his appetite(食欲) and he ate much less than before. His mother made him drink a grass of orange every few hours for more Vitamin  C. For two days he was nursed by his mother, and I began to feel weak. I knew I had to leave him before long. Because of his defense system (防御系统) was starting an all-out attack(袭击) against me, I became weaker and finally my time was over. Do you know what ' I ' am? 1. According to the passage, 'I' am ________. A. a mother B. a doctor C. a reporter D. the flu (流感) 2. Which of the following is NOT the reason for the student getting ill? A. An unexpected change of the weather. B. He was too tired. C. He went to a crowded place. D. An immediate(立即的) cold shower. 3. The underlined word 'victim'means a person who was ________in the second paragraph. A. happy B. friendly C. injured D. healthy 4. 'I' felt ________after the mother nursed the student. A. confident B. energetic C. bored D. weak 5. What can be inferred (推断) from the passage? A. Many people can not look after themselves well. B. It's easier to get a cold in the hot summer. C. You can keep away from the cold only by having more Vitamin C. D. The cold can be kept away when the defense system started to work.