Carl studied in our middle school three years ago. Last August his father found a job in another city and his family moved there. He began to study in the new school and we often write to each other. He often tells me something about the city where he lives now and his studies in the school. So I can know what happens to him. Last Friday Carl came to our city again. He hoped to accompany  his old grandpa during the summer holiday. He was taller and stronger than before. We swam in the river outside the city together and had a picnic on the island. It surprised me that he had learnt to cook when we were traveling in the wild forest. He told me his parents were both busy and sometimes he stayed at home and he had to look after himself. "How do you like your school?" I asked. "Wonderful," said the young man." It has a tall building and there 're two chemistry labs, two biology labs and three physics ones. And its library is big and there're plenty of books in it." "I can see you are satisfied with it." "Yes," he answered. "But our geography teacher often says it himself in class." "So does our new history teacher." I said. "But he doesn't notice it. He often talks on and on in a flow of the eloquence , but none of us listens to him." Carl is satisfied with his school because  _  .
his teachers work hard. it has lots of books it has several labs. it's wonderful.