阅读短文，回答问题。
It's a fine Saturday. The weather is nice. Two brothers often go to climb mountains. Jack is tall and smart.
John is short and funny. There is a beautiful forest in the mountain. Near the forest, there is a big lake. There are
many fish in the lake. In front of the lake, there is a river. They can see a bridge over the river. They take some
pictures on the bridge. They want to go to the nature park, but they have no time.
1. What do Jack and John do on Saturday?
2. Is John thin?
3. Where is the lake?
4. Is there a bridge over the lake?
5. Do they go to the nature park?