What was discovered by accident? The answer is penicillin (青霉素). It kills germs. By killing germs, it saves lives. Suppose you are sick. You go to a doctor. She examines you. She says you have a “staph” infection (葡萄球菌感染). She gives you some medicine. You take it. The medicine knocks out the staph. Soon you are well. Before penicillin, this would not happen. Staph was almost sure death.

　　Everyone wanted a medicine. Laboratories worked day and night. They grew the staph in small dishes. Then they tried to kill it. Nothing worked.

　　The laboratory dishes had covers on them. They kept things from falling into dishes. Molds (霉菌) were a big worry. They are always in the air. You can’t see them. They’re too small. There are thousands of different molds. Molds can make an experiment (实验) fail. That’s why dishes are covered.

　　Dr. Alexander Fleming was working to kill the staph germ. He worked for years. One day he took a cover off a dish. He looked inside. There was a thick growth of staph germ. There was also some mold. Then he saw something strange. Where the mold was, there was no growth of staph. This is what Fleming probably thought. “By accident, I found a mold to kill the dreaded staph.”

　　This is how penicillin was found. But here’s the real miracle (奇迹). There are thousands of kinds of molds. But only one kind can kill staph. The mold must have fallen into the dish a few days before. The cover was probably off only a few seconds (秒). In those few seconds the right mold fell into the right dish. Another man might have thrown the dish away. But Fleming was very careful and smart. He understood what the mold did. How lucky the humans were!

　　根据短文内容，选择最佳答案

　　21. During the experiments to find a medicine for staph infections, ________.

　　A. the dishes were not covered

　　B. staph and mold were put together

　　C. mold was kept in small dishes

　　D. staph was grown in small dishes

　　22. The word “ dreaded” means “_______”.

　　A. famous    B. scary

　　C. health    D. endangered

　　23. The last paragraph suggests that _______.

　　A. accidents happen to everyone

　　B. the careful person does not have accidents

　　C. the careless person will miss valuable chances

　　D. luck is enough when doing scientific experiments

　　24. Most of this passage is written by ______.

　　A. telling an unusual story    B. showing the results of experiments

　　C. offering some reasons    D. giving some advice

　　25. This passage is mainly about ______.

　　A. medicine for a staph infection    B. useful accidents

　　C. Dr. Fleming’s research    D. discovering penicillin

　　【答案】21. D    22. B    23. C    24. B    25. D

　　【解析】

　　【分析】

　　短文大意：本文介绍了青霉素在实验室的意外发现以及主要用途。

　　【21题详解】

　　题意：在寻找葡萄球菌感染的药物的实验中，      。考查细节理解题。A. the dishes were not covered盘子没有被覆盖。B. staph and mold were put together把葡萄球菌和霉菌放在一起。C. mold was kept in small dishes模具放在小碟子里。D. staph was grown in small dishes葡萄种在小碟子里。根据第二段第三句They grew the staph in small dishes.可知，在实验的过程中，青霉素是在密封的盘子里生长的。故选D。

　　【22题详解】

　　题意：“dreaded”这个词的意思是      。考查词义猜测题。根据第一段You go to a doctor. She examines you. She says you have a “staph” infection，葡萄球菌能让人生病，可知它是“可怕的”，故选B。

　　【23题详解】

　　题意：最后一段暗示了      。考查推理判断题。根据最后一段中There are thousands of kinds of molds. But only one kind can kill staph.，有数以万计的霉菌，但只有一个能杀死葡萄球菌，可知只有细心的人才能发现霉菌杀死葡萄球菌，粗心的人是得不到有价值的东西的，故选C。

　　【24题详解】

　　题意：这篇文章的大部分都是通过      撰写的。考查综合理解题。根据短文内容，整篇文章都是通过实验介绍青霉素和霉菌是怎样被发现的，故选B。

　　【25题详解】

　　题意：这篇文章主要是关于      的。考查主旨大意题。A. medicine for a staph infection用于葡萄球菌感染的药物；B. useful accidents有用的事故；C. Dr. Fleming’s research Fleming博士的研究；D. discovering penicillin发现青霉素。通读全文，本文介绍了青霉素在实验室的意外发现以及主要用途，故选D。

　　【点睛】对于阅读理解题，首先要粗读文章了解大意，其次通过细读，理解全文。在粗读的基础上，仔细阅读题后所给的题目，根据题目要求，再有重点地返回来仔细阅读。在阅读理解的题目中，所设问题主要有以下几种方式：找主题或概括文章的中心思想、就文中的具体事实和情节进行提问、根据文章的表层意思进行深层次的推理判断等，在细读时，要根据设问的方式，进行有侧重地阅读。1、概括文章中心思想。1)文首呈现主题句。2)文尾出现主题句。3)首尾呼应展现主题。4)文中表述主题。前面提出问题，文中的主题由随之陈述的细节或合乎逻辑的引申在文中导出，而后再做进一步的解释。5)文章没有主题句。在这种情况下，考生要把所有的细节综合起来。进行逻辑推理，概括归纳出文章的主题句。2.掌握文章的具体事实和重要情节。在考题中，经常会见到就文章中某一具体事实和重要情节进行测试的题目。这就要求考生在阅读时要注意辨认和记忆具体事实，重要情节，事物的起因、过程、结果及发生的地点、时间等，这些都有可能作为测试点。还有一些测试题，要求考生在理解的基础上，通过自己的思维将理解的内容系统化，比如计算、排序等题型。