As a volunteer(自愿者) teacher, I traveled a long way to a small village school in Longzhou, Guangxi. On my way there, I thought about the village, the school and the childrenn there. However, my heart sank when I arrived there. It wasn't what I expected. It didn't look like a school at all! The school had only three rooms, one for Grades 1, 2 and 3, and the other for Grades 4, 5 and 6. There was a third one for me.
　　The children welcomed me warmly on my first day. They asked me a lot of questions, and I told them stories about myself and my life in Shanghai. The next day, I gave them a test to find out their level（水平）. To my surprise, though the test was very easy, over half of the students failed it, yet they all wanted to learn new things. I knew they needed me.
I was busy preparing lessons and reading test papers every night. I enjoyed teaching these lovely and hard-working children, and I could see that they were making progress(进步) with my help. I have also learned a lot from them. I understand their level is becoming higher and higher, and we are good friends now.
I worked in Longzhou for a year. I'm very happy, and the experience(经历) is very useful to me. I love the small village and the children. In fact, I would like to continue working here.
【小题1】How many grades are there in the school?