A、Because they can prevent other bacteria’s overgenerating. B、Because they can keep your hands clean. C、Because they let other b

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. (26) Washing your hands helps remove the bacteria that are just visiting from foreign places like the sink,the door and even other people’s hands. However, washing couldn’t remove your hands’ own resident bacteria, which is really terrible. While it’s hard to imagine your hands as a bacterial homeland,these residents are perfectly normal and are important in maintaining your health. (27)They help prevent the other bacteria 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 the other bacteria which come from foreign places move in and cause disease. Finally, over-washing could break down the skin itself. (28) This allows harmless skin residents to go beneath the skin, where they can become dangerous. So, while a good wash with soap and water is still a great idea, overwashing might lead to some unpleasant symptoms. (29) In conclusion, it is not wrong to keep your hands clean by washing them as often as possible,but what is more important is that try to make it reasonable and scientific.
26. What can be removed by washing hands?
27. Why are resident bacteria important in maintaining your health?
28. What will happen after skin is broken down by over-washing?
29. What does the speaker say about washing hands?