You have received a letter from your English-speaking pen friend, Alex. "I'm thinking of going rock climbing but my parents say it's too dangerous. Have you ever been or would you like to go rock climbing? Do you think sports like that are dangerous? Which outdoor sports activity would you recommend for someone who doesn't want to do something too adventurous?" Write him a letter and answer his 3 questions. Write 100-120 words, Remember the rules of letter writing.