Read and answer. Jack为什么回家晚了？读一读，回答下列问题。
Jack is a naughty (顽皮的) boy. He walks to school every day. The school is near his house. He comes
home on time (准时). But today he is late. His mother asks him, "Why are you late (晚了) today ?"
"I am in the teacher's office." "Why do you go to the teacher's office ?"
"Because my teacher asks us a question in class, and nobody (没有人) can answer it, but I can."
"It's good to answer the teacher's questions." his mother says.
"But the question is who makes the teacher's desk dirty ?"
1. Is Jack a naughty boy ?
2. How does Jack go to school ?
3. Why is Jack late today ?
4. Who makes the teacher's desk dirty ?