Different from popular thoughts, sometimes flu（流感） is not caused by bad weather. It is caused by viruses in the body. 51 , A/H1N1 flu has been spreading in the most parts in the world. Some studies have now shown that one of 52 ways of spreading the viruses is through the air when 53 A/H1N1 flu-sufferer coughs or sneezes. However, its viruses can sometimes spread by 54 （面纸） to clean his running nose, although his parents pick up the tissues and carefully throw 59 away, they fail to wash their hands, and they will catch the viruses, too. So it is important for you to wash your hands often, it will stop the viruses from 60 in a way.. After a flu-sufferer rubs his nose, the viruses might be spread to his hand. Then a friend 55 to visit him, they shake their hands. The friend then gets something 56 by hand, and several days 57, he is infected. A child 58 is carrying A/H1N1 viruses uses tissues
