根据短文内容在空白处填入适当的单词。

      It's Sunday morning. Many boys and girls are in the park. Some of them are singing under the tree, some are  in the river, other children are playing games behind the hill.

      Maria is  American girl. She is in the park, too. Where is she? Oh, she is on the hill. What is she  over there? She is sitting and  a book. She likes reading very much. Tom is an English boy. He is five. He is too young. He can't go to school. Now he is  a kite with his father in the park.