One of the best-known American writers of children's books is Alfred Strong, or Doctor Strong, as he is better known to readers everywhere．Now, an art show called "Doctor Strong From Then to Now" is travelling around the United States．The pictures and drawings show the history of Doctor Strong．

    Doctor Strong first became famous almost fifty years ago when his first children's book was published (出版)．Since then, he has written forty—five books that have been sold more than one hundred million copies around the world．

    Doctor Strong's books are known for their easy use of words and colourful, hand drawn pictures．These drawings bring life to his imaginary creatures, The Cat in the Hat, Horton the Elephant, The Grinch Who Stole Christmas, and hundreds of others．

    The San Diego Museum, in California, organized the art show．It included about three hundred Doctor Strong's early drawings and some of his writings．

Most of Doctor Strong's books, although written in a funny way, have serious messages．For example, in McElligot's Pool, he describes the danger of pollution．He discusses the arms race (军备竞赛) in The Butter Battle Book, written in nineteen eighty four．

    Doctor Strong says he never planned to write stories just for children．He says he writes stories that interest people of all ages．He says he uses easy words so that everyone, even a child, can understand．