The worst experience of my life happened when I was in the fourth grade of elementary school. At my elementary school, after the noon recess, we always had a clean-up time. We cleaned our classroom, the entrance, and the passageway. Usually, we swept the floor and wiped the floor with a floor cloth. We liked to wipe the floor with a floor cloth because we had a race wiping the floor. We stood in a row, started at the same time, went straight, and wiped the floor as fast as we could. Since the passageway was relatively long, the race was exciting. We liked the charge of cleaning the passageway. At that time, my group which was composed of six members was in the charge of cleaning the passageway. As usual, after we swept the floor, we had the race. When we started at the same time and went straight, the worst thing happened. I stumbled over a little bump and fell, and my face ran hit the floor. My friend was worried about me, and I was very ashamed. Because of this happening, my front teeth were chipped. I had to have a brace with front teeth for about a month after then. That is my worst experience.