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　　Most people believe that regular hand-washing is the best way to prevent infections. And they’re right: hand-washing does prevent certain infections, but too much washing can actually help some infections along.What’s going on?

　　Right now, there are millions of bacteria from hundreds of different species happily residing on your hands, not to mention your teeth, gums, eyes and ears. These bacteria are either transients or residents. Washing your hands helps remove transientbacteria that are just visiting from foreign places like the sink, doorknob and even other people’s hands. Washing shouldn’t remove your hands’ own resident bacteria,though.

　　While it’s hard to imagine your hands as a bacterial homeland, these residents are perfectly normal and are important in maintaining your health. They help prevent transientbacteria from settling in, and each resident keeps other residents from overpopulating.

　　If you scrub your skin too frequently, especially with anti-bacterial soap, you could upset resident bacteria, leading to the overpopulation of certain species and local skin infections. Scrubbing away residents might also let transients move in and cause disease. Finally, over washing could break down the skin itself. This allows harmless skin residents to go beneath the skin, where they can become dangerous transients.

　　So, while a good wash with soap and water is still a great idea, overwashing might lead to some unpleasant symptoms, not to mention inflamed and unsightly hands.

標簽：有趣一節(jié)課

熱門成語

• 枯木朽株  枯木頭，爛樹根。比喻衰朽的力量或衰老無用的人。
• 愧天怍人  怍：慚愧。對天對人，都感到慚愧。指做了虧心事無臉見人。
• 平治天下  平：平定；天下：指全中國。治理國家，使天下太平。
• 然荻讀書  然：“燃”的本字，燃燒；荻：蘆葦一類的植物。燃荻為燈，發(fā)奮讀書。形容勤學苦讀。
• 束手旁觀  猶袖手旁觀。比喻置身事外，不加過問。
• 宋畫吳冶  用以作為精巧神妙之物的代稱。
• 土階茅茨  比喻住房簡陋。同“土階茅屋”。
• 延頸鶴望  像鶴一樣伸長頸子盼望。比喻盼望心切。
• 至死不渝  至：到；渝：改變。到死都不改變。
• 諸如此例  許多像這樣的事例。
• 抓破臉皮  比喻感情破裂，公開爭吵。
• 黃發(fā)垂髫  黃發(fā)：老年人頭發(fā)由白轉黃；垂髫：古時單童子未冠者頭發(fā)下垂。指老人與兒童。
• 魯陽指日  同“ 魯陽揮戈 ”。 清 吾廬儒 《京華慷慨竹枝詞·電燈》：“大地茫茫日暮時， 魯陽 指日日仍馳?！?/span>