对产褥热进行研究的是：（）。 A: JohnSnow B: IgnazPhilippSemmelweis C: JamesLind D: JohnLast E: 李时珍

1948年英国医生JohnSnow利用哪一流行病学原理和立法提出和论证了霍乱流行饮用水污染的关系？（） A: 病例——对照研究 B: 定群研究 C: 季节性分布分析 D: 地区分布描述 E: 理论流行病学

B)<em>Readthefollowingpassageandinfilleachblankwithonewordinoneofthefollowingthreeways</em><em>：</em><em>①</em><em>accordingtothecontext</em><em>,</em><em>②</em><em>usingthecorrectformofthewords</em><em>,</em><em>or</em><em>③</em><em>accordingtothegivenletter(s)oftheword</em><em>.</em>(阅读下面的短文，用以下三种形式之一完成短文填空：①根据上下文填空；②用所给单词的正确形式填空；③根据单词所给字母填空。每空一词。)<br/><alone></alone>Choleraisadiseasespreadbydirtywater,eitherwhenpeopledrinkthewater,(51)______eatfoodwhichhasbeenwashedinthewater,andnot(52)______(proper)cooked.Unfortunately,untilthemid19thcentury,peoplebelievedthatthedisease(53)t______throughtheair.Inthe(54)______(crowd)citiesof19th-centuryBritain,choleraspreadeasily.Mostdoctorswronglybelievedthatfreshairandabetterdietwould(55)p______thedisease.Hugefireswereusuallylitinthestreetstodrive(56)______theinfection,andtheclothesofvictimswerealsoburned.Thestreetswerealsocleanedthoroughly(57)w______powerfulchemicals.However,peoplecontinuedtosufferdreadfully.In1854,adoctorinLondon,JohnSnow,announcedwithcertaintythatcholeraspreadthrough(58)i______drinkingwater.Hedidthisbycarefully(59)______(collect)statisticsabouttheinfectioninonepartofLondon.Hemanagedtoprovethatthewaterwas(60)______(entire)responsibleforcholerainfection.