将下列单词或词组填入空格。每空格限填一词，每词或词组只能填一次

    Young people like to be cool. What's cool? Different people have different  . Some people think they are cool if they wear fashionable(时尚的) clothes. Some people think if they have hairstyles(发型), they are cool. Some people think they are cool when they wear fewer clothes in winter. But I don't think so. I think you are cool when you are healthy. How to  ? Exercise every day, such as running, walking, swimming. Exercise can  people healthy.  People can exercise with their parents friends. Exercise can be fun and they can help people keep healthy. So why not exercise every day?