They are the sort of friends who are so close that they trust each other with their lives.If one falls，the other is there to catch him.

　　They are Wellman，whose legs were permanently injured nine years ago in a rock-climbing accident，and Corbett，an experienced rock climber.Together，they climbed up Half Dome，the famous 2,000-foot rock in the Yosemite National Park，through one of the most difficult routes.

　　During the climb，Corbett took the lead，hit in the metal spikes(尖状物) that guided the ropes and climbed up.Then，after Wellman pulled himself up the rope，Corbett went down to remove the spikes and climbed up again.This process was repeated time and time again，inch by inch，for 13 days.

　　Wellman's job was not easy either.He got himself up the rope through upper body strength alone.In all，Wellman figured that he had done 5,000 pull-ups up the rope on the climb.

　　However，when the two men first met，they never talked about climbing."He knew that was how I got in-jured，" Wellman said.Until one day Wellman decided that he wanted to climb again and they started training.

　　Their climb of Half Dome was not all smooth.At one point，pieces of rock gave way，and Corbett dropped down quickly.Wellman locked their rope in place，stopping the fall at 20 feet.His quick action probably saved his friend's life.

　　"Your partner can save your life-you can ，" Wellman said as the pair received congratulations from friends."There are real close ties."

根据上文完成下列各题

1．Why did the two men never talk about climbing when they first met?

Corbett didn't want to hurt Wellman.

2．Fill in the blank in the last paragraph with proper words.

save your partner's life

3．What's the main idea of the text?

Friendship is precious in life.