The mobile phone is a useful invention. It helps us in our daily lives. We can talk with friends with phones. We can buy things with them. We can take lots of beautiful pictures with them, too. Many children think that mobile phones are cool. They like to have a mobile phone, so they can talk with friends at any time and any place. However, most of the children do not think about (考虑) the health problems of using mobile phones. Some scientists say that mobile phones give off radiation(辐射). The radiation may be bad for people's health. A study says that the radiation of mobile phones can have a chance of getting some kinds of cancer(癌症). But other scientists say that they don't find any links(关联)between mobile phones and cancers. Scientists say that people can protect themselves from mobile phone radiation. One way is to use a headset(耳机). Or people can make short phone calls.