Item 1 : The most common disease in the world is the cold . It often starts with a sore throat . You sneeze and your nose runs . You usually have a headache , too . Often you have a cough later . It's not a serious disease , but you can feel quite bad . There isn't a cure ( 良药 ) for a cold , but you can take medicines to make you feel better . For example , you can take aspirin ( 阿司匹林 ) to get rid of your headache . It is good to rest , and to drink a lot of water, too . Item 2 : What makes us ill? It is germs ( 细菌 ). Germs are everywhere . They are very small and you can't see them with a microscope . They are very small and there could be hundreds of them on a very small object . Germs are always found in dirty water . When we look at dirty water under the microscope , we can see them . This is why your parents stop you drinking dirty water . Item 3 : It is very important to keep yourself in good health . If you are sick , you can neither study nor enjoy yourself . One of the factors ( 因素 ) leading to good health is a balanced diet . You need to eat more fruits and vegetables which contain ( 包括 ) a lot of fiber ( 纤维 ).