I   this school for over two years.

I  the bike for only three weeks.

假若你是健康专家李教授，你被邀请到一所中学给学生作一场健康方面的讲座。请根据以下内容写一篇发言稿。80词左右，开头和结尾已给出，不计入总词数。

Hi, everyone,

Today I want to talk about how to keep healthy. I hope my advice will help you.

……

If you can follow my advice, I am sure you can be in good health. Thanks for listening.

Hawking   for about three years.

Mary  the book for three weeks.

Mr Wang    our school 2017.

The film   for half an hour.

The dog   for three days.

There was a boy called Billy. Billy's favourite 1 was orange. But he couldn't see what orange 2.

A month after he was born, his mother 3 that his eyes weren't as big as a normal boy's." Billy would 4 be able to see. He is blind," the doctor said. Even so, with the hope to help Billy learn about the world around 5 ， his mother kept describing (描述) everything she saw to him.

Not just through his mother's words, Billy saw 6his ears and hands， too. He had perfect hearing. In fact， he 7see many things that normal(普通的) people don't notice.

 8 Billy lived in the dark, he always believed a dream would light up his life. He found that he was 9 in computer science. So he 10 learning it at seven years old. As a young boy, he 11 going to Stanford University some day. And for years of efforts, he finally 12. his dream.

Many people wanted to find out the secret of his 13. Billy explained, "Just move forward! Don't let any difficulty  14your dream from coming true.

You cannot choose what you are given， but you can choose 15 to make use of it.

Patsy was in hospital. Her friend Mary went to see her. She found her lying in bed, covered with bandages (绷带).

"Well, when I got to the hospital, the doctor gave me. some medicine to stop the pain in my leg and I fell asleep. Unfortunately, he made a mistake with my name."

"And another doctor operated(手术) on your arm!" Mary said.

"That's right," Patsy said. " But I shouldn't complain(抱怨). My own doctor was right. The walk in the park was good for me. My headache has completely gone now.