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当前学科：人群健康研究的流行病学原理和方法
题目：
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流行病学中的偏倚属于（）
A . 抽样误差
B . 系统误差
C . 随机误差
D . 数据误差
E . 逻辑误差
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A Dangerous PlacePaula had always wanted to go to New York and now she had the chance at last. She was a journalist, and her newspaper was sending her there to do a series of articles on the city. But before she left her home in London, several friends warned her to be careful and not to go out alone at night in New York. "It's a dangerous place. People get robbed or even killed in broad daylight!" they told herBut once she got there, she was oniy afraid of exhaustion. It was so stimulating and exciting a city that she never got any steep. It took her two weeks to do the articles and she had to interview a lot of people, but she enjoyed every minute. She completely forgot all her friends' warnings until the day before she went back to London. It atl began in a barShe was having lunch there when she suddenly felt someone was watching her. She looked up and noticed a man sitting at a table opposite her. He was staring at her, but looked away. She noticed that he had a scar on his cheek. He was about 30, and had short, curly hairPaula was not worried at all then. She had to go to an airline office to book her flight home. She wanted an afternoon flight instead of a morning one. On her way there, she stopped to look at something in a shop window. To her surprise, she saw the man following her; she could see his reflection in the glass. He had stopped just behind her. Suddenly she felt afraid. She walked on. Then she stopped and looked behind her again. But this time she could not see him.Just then she noticed she had come to the airline office. She went in. After she had finished her business, she decided to phone a friend from a telephone booth there. She was carrying a small, portable but very expensive tape recorder. It was in a black case. She kept her money and passport in the case as well. But the booth was so cramped that she had to eave the case outside. When she came out, it had disappeared. She was stunned. Then she saw the red-haired man hurrying out of the office. He had the case in his hand. She shouted, but it was too late.Read Passage and answer the following questions. Make your answers as short and clear as possible. Write your answers on the Answer Sheet31.Why did Paula go to New York?32. What did her friends tell her before she left London?33.What did the man sitting opposite her look like?34. What did she keep in her black case?35. What happened at last?
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