The Magic Tree House

　The Magic Tree House is a book series by US writer Mary Pope Osborne. The first book starts with Jack and Annie Smith. They are brother and sister. They find a mysterious(神秘的) tree house while playing in the woods. The books are then split(拆分) into two groups.
　In the first group of books, Morgan le Fay, a sorceress(女巫), tells Jack and Annie to find something or meet a special person at a certain time and place. The Tree House magically takes them there. They learn about the fashion, society(社会), people and more about that time and place. These stories are short and easy to read. We learn about famous historical figures(人物) and events of the past, through fun and exciting adventures(冒险).
　In the second group, however, stories become longer and harder to read. In these books, the ancient wizard(巫师), Merlin, sends them to fantasy lands. We can learn about the legends(神话) of different cultures.