When I was young，I liked to play jokes on people I knew， especially on my parents and friends. One day my mother was cooking and I was playing with my younger brother Tony. Suddenly I ran to my mother and said： “Tony fell from the open window!” She was very worried and ran out of the kitchen. Then I said： “Don’t worry， I’m just joking.” My mother shouted at me， “If you do it again， I’ll hit you.”
Another day I went swimming with my friends in the sea. I wanted to play a joke on them. In the beginning I swam fast and I called out “Help!”. All my friends came to help me. However， they found that I was joking. But half an hour later I wasn’t joking. I was so fast， soon I got tired and couldn’t swim on in water. I tried my best to call my friends for help， but this time nobody came to help me.
In the end they found I was telling the truth. They came and saved my life. They took me to the hospital. This is the best lesson in my life. From then on I haven’t joked on anyone.
What happened when the writer was playing with his younger brother?

A．He got tired.

B．He played a joke on his mother.

C．Tony fell from the open window.

D．His mother hit him.

When the writer called his friends for help for the second time， they________.

A．took him to the hospital at once

B．came and saved him immediately

C．thought at first he was joking again

D．did nothing because the writer had lied to them

The story tells us that _____________.

A．swimming is dangerous

B．the writer is a naughty boy

C．one can play jokes only on people he knows

D．if someone always tells lies， others won’t trust him