This summer I will leave the junior high school where I have been for three years. I am generally considered to be a careful and polite boy now. However, five years ago, I was a little bit bossy . I often fought with other boys and sometimes I even fought with my elder sister. When I saw Superman on TV for the first time, I dreamed of being a superman one day. One P.E. class, I called up all of my friends to get together in our classroom. "Can anybody jump out of the window?" I asked them. After hearing this, all my friends kept silent. " _ ," I said. "Can you?" one of my friends asked me. "Sure!" I answered. "If I do it, I will get all the toys that you have. If I fail, you will get all of my toys, OK?" They said, "OK!" Then I went up to the window of the second floor. I took a deep breath and then jumped down, stretching out my arms just like Superman. Then I hit the ground. When I opened my eyes, I found myself lying in the hospital. I was taken to the hospital because my arms were badly hurt. Later, I heard that my P.E. teacher nearly lost his job for this, but I never received the serious punishment I feared. The story happened when the writer was in   _   .
university elementary school junior high school senior high school