题目内容：

When I was young, I liked to play jokes on people I knew, especially on my parents and friends.

One day my mother was c1.in the kitchen and my younger brother was playing outside. I ran to my mother and said, “My brother has fallen from the s2.in the garden!” Mom was very w3.about my brother, and I laughed, “Take it easy! I’m just joking.” And my mother s4.at me，“If you do it again，I’ll punish (惩罚）you.”

One day I went swimming t5.with my friends in the sea. I wanted to play a joke on my friends. In the beginning, I went swimming by m6., then I called to my friends,

“Help me!” All my friends eame to help me，only to find out that I was joking. But the next time I wasn't joking. I swam in the deep water and I was so careless that I was a7.drowned (淹死）.I t8.my best to call my friends for help, but this time n9.of them came to help me.

Luckily，they found the tmth (事实），so they came quickly and saved my life. From then on, I haven't joked on a10.anymore. I think this is the best lesson in my life.