阅读短文, 补全下面的思维导图。 

It's a fine day today. Jack and his friends are in the park. They see lots of interesting things. Some kids are rowing a dragon boat on the lake. Two men are playing chess under the tree. What are the boys doing? Oh, they are riding bikes. Some girls are taking pictures of the flowers. What's Jack doing? He is doing exercise. What are Alice and Mary drinking? They are drinking milk.