读短文，回答问题。 Peter went to the library yesterday. He got up early and went to the library after breakfast. Usually Peter goes to the library by bus and that day he had a new idea.  He went by his new bike. In the library he saw some new science books and he really wanted to read them all but he couldn't. He could only have three books at a time. He took the books and walked out of the library. He went to his bike but he couldn't open it with his key. What was wrong? He looked at the key and then looked at the bike. Oh, no. It wasn't his. His bike was next to it on the right! 1. How does Peter usually go to the library? 2. How did Peter go to the library that day? 3. What did Peter see in the library? 4. Why he couldn't open the bike?