This March, the H7N9 virus hit Zhejiang, Shanghai, Anhui, Jiangsu and so on. It seemed that most people who were infected with H7N9 had the common flu. Some people suffered from a fever or a cough. Don't be afraid---it's not easy to be infected with the virus. Here is some advice to help you protect yourself when it comes. Wash your hands. You need to wash your hands with soap and hot water before you eat, after you use the toilet , and after you touch animals, because your hands may carry viruses. Cover your nose and mouth, when someone sneezes or coughs, flu viruses can travel as far as one meter through the air, so you'd better stand a proper distance while talking to someone who has a cold. And always cover your nose and mouth with a piece of paper when you sneeze or cough, and then clean your hands. Wear a mask . Some doctors say that masks can stop the flu as much as 80%, but if you don't wash your hands often, it's no use wearing a mask. And it's necessary to wear a mask in the groups of people. Do sports often. Exercise will help your body strong enough to _ the virus. Which of the following is TRUE according to the passage?
Some people who were infected with the H7N9 virus had a toothache. You should cover your mouth and nose with a piece of paper when you sneeze or cough. Some doctors say that washing your hands can stop the flu as much as 80%. It's easy to be infected with H7N9 virus, so you mustn't go to the places with groups of people.