People in different countries use different types of 1 yuan in China, pesos in Mexico, pounds in the United Kingdom, dollars in the United States, Australia and New Zealand. They may use 2 currencies, but these countries, and probably all countries, still have one thing in common1: Germs on the banknotes.
Scientists have been studying the germs on money for well over2 100 years. At the turn of the 20th 3 , some researchers began to suspect that germs living on money could spread disease.
Most studies of germy money have looked at the germs on the currency 4 one country. In a new study, Frank Vriesekoop3 and other researchers compared the germ populations found on bills of different 5 .
Vriesekoop3 is a microbiologist at the University of Ballarat in Australia4. He led the study, which compared the germ populations found on money 6 from 10 nations. The scientists studied 1,280 banknotes in total; all came from places where people buy food, like supermarkets street vendors and cafes, 7 those businesses often rely on cash.
Overall, the Australian dollars hosted the fewest live bacteria ---- no more than 10 per square centimeter. Chinese yuan had the most ---- about 100 per square centimeter. Most of the germs on money probably would not cause harm.
What we call paper money usually isnt made from paper. The U. S. dollar, for example, is printed on fabric that is mostly 8 .Different countries may use different 9 to print their money. Some of the currencies studied by Vriesekoop and his 10 such as the American dollar were made from cotton. Others were made from polymers.
The three 11 with the lowest numbers of bacteria were all printed on polymers. They included the Australian dollar, the New Zealand dollar and some Mexican pesos.
The other currencies were printed on fabric made 12 of cotton. Fewer germs lived on the polymer notes. This connection suggests that 13 have a harder time staying alive on polymer surfaces. Scientists need to do more studies to understand how germs live on money-----and whether or not we need to be concerned. Vnesekoop is now starting a study that will 14 the amounts of time bacteria can stay alive on different types of bills.
Whatever Vriesekoop finds, the fact remains: Paper money harbors germs We should wash our 15 after touching it; after all5, you never know where your money s been. Or whats living on it.
雅思阅读考场技能训练方法略读细读交叉运用
雅思口语快速提升大法注意选材短文复述
考生注意考试的准考证打印时间提前了
雅思阅读好帮手盘点连接上下文的信号词
雅思阅读各题型的难度及解题策略巧用文章标题
精准定位三类不同考生的雅思听力备考策略
雅思剑9即将发布听力完成句子题仍将是重点
雅思口语考试应该要把握的两大高分原则
雅思口语素材:英文经典长句汇总
雅思口语盘点中国学生口语分数低三大原因
黄金法则不同题型的雅思阅读题解答技巧
雅思宝典:写作高分备考的七大关键点
雅思秘籍大公开多元化视角透析雅思阅读
高效准备雅思考试技巧内功修行题海战术
雅思阅读高分的三个策略
雅思阅读词汇量之外的四大重要技能
雅思阅读中T/F/NG类题型四大疑难考点分析
世界杯32强口号巴西最霸气意大利很浪漫
提高雅思成绩的10个建议
盘点托福阅读与雅思阅读备考的不同
雅思听力中生词不认识你照样可以读懂题目
雅思阅读辅导8组常见的关系词拯救阅读困难户
雅思听力的五步备考策略摆脱听力难题不是梦
高效备考雅思阅读的经验分享
2月23日24日雅思口语机经汇总及备考指导
雅思写作满分作文准备方法四则快速提高成绩
合理安排雅思阅读做题顺序充分发挥英语水平
阅读做题技巧通过关键词判断作者意图
雅思技巧雅思阅读不同题型通用的解题小技能
雅思口语考试的扣分细节
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |