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题目：
多选题
以下是传染病流行的环节的是
- A. 患者
- B. 病原携带者
- C. 传播途径
- D. 易感者
- E. 隐性感染者
答案：
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药材乌梢蛇原动物的科名是（）
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Shopping habits in the United States have changed greatly in the last quarter of the 20th century. （1） in the 1900s most American towns and cities had a Main Street. Main Street was always in the heart of a town. This street was （2） on both sides with many （3） businesses. Here, shoppers walked into stores to look at all sorts of merchandise: clothing, furniture, hardware, groceries. （4）,some shops offered （5） .These shops included drugstores, restaurants, shoe-repair stores, and barber or hairdressing shops. （6） in the 1950s, a change began to （7） .Too many automobiles had crowded into Main Street （8） too few parking places were （9） shoppers. Because the streets were crowded, merchants began to look with interest at the open spaces （10） the city limits. Open space is what their car-driving customers needed. And open space is what they got （11） the first shopping centre was built. Shopping centres, or rather malls, （12） as a collection of small new stores （13） crowded city centres. 14 by hundreds of free parking space, customers were drawn away from （14） areas to outlying malls. And the growing （16） of shopping centres led （17） to the building of bigger and betterstocked stores. （18） the late 1970s,many shopping malls had almost developed into small cities themselves. In addition to providing the （19） of one stop shopping, malls were transformed into landscaped parks, （20）benches, fountains, and outdoor entertainment. 请在17处填上正确答案（）
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王清任认为灵机记性（）
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背景材料： 某公路工程施工总承包二级企业承包了单跨跨度为120m的桥梁工程项目，桥梁上部结构施工中出现垮塌事故。监理工程师立即报告建设单位，施工单位着手事故处理。 （1）该总承包二级企业能承包该工程吗？说明理由。 （2）该质量事故的调查处理由谁负责？ （3）该质量事故由谁负责报告？
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爆炸和火灾危险场所的电缆和绝缘导线，其额定电压不应低于（）V。
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一种牛场要选择一批奶牛，它们一个泌乳期的产奶量分别为：一号为3122公斤、二号为2994公斤、三号为4100公斤、四号为3812公斤、五号为3588公斤、六号为2997公斤、七号为4355公斤、八号为3889公斤。试用表型选择法选出两头头奶牛留种，应该选择的奶牛序号是（）
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酚钠盐的分解，通常有（）分解法和（）分解法两种。
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血站涉及的血源，采供血和检测的原始记录，必须保存多少年（）
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下列关于“环境污染”概念的描述正确的有()。