Everyone faces challenges in their life，but some are more important than others．Daniel Kish had serious problems with his eyes when he was born．And doctors took away both of his eyes before he was fourteen months old．

Soon after，however，he started to do an amazing thing．He started to make clicking（咔嗒）sounds with his tongue（舌头）to help him move around．Much like a bat（蝙蝠），he now moves about using sonar（声呐）．He is so good at it that he can ride a bicycle in traffic．He and his group， World Access for the Blind，teach others how to use sonar．In this interview with National Geographic，Kish explains how the process works．

How does sonar work ？

"When I make a clicking sound，it makes sound waves．These waves reflect（反射）off surfaces all around and return to my ears．My brain then processes the sounds into images（图象）．It's like having a conversation with the environment．"

When you click ， what do you see in your mind ？

"Each click is like a camera flash．I make a 3D image of the things around me for hundreds of feet in every direction．"

What is it like riding a bike using sonar ？

"It's exciting and enjoyable but requires a lot of focus．I click up to two times per second，much more than I usually do．"

Is it dangerous to move around the world in this way ？

"Much of the world lives in fear of things that we mostly imagine．I have a habit of climbing anything and everything，but I never broke a bone（骨头）as a kid．"

How challenging is it to teach people to use sonar ？

"Many students are surprised how quickly results come．Seeing isn't in the eyes；it's in the mind．"

（1）What's the main idea of Paragraph 2？ 　　

A．	Kish explains how sonar works．
B．	Kish teaches people how to use sonar．
C．	Kish started to move around using sonar．
D．	Kish is good at riding a bicycle in traffic．

（2）How does sonar work？Choose the right order 　　．

a．The sound waves reflect off surfaces．

b．The person makes a clicking sound．

c．The brain makes images with the sounds．

d．The sound waves reach the person's ears．

A．	b﹣a﹣c﹣d．
B．	b﹣d﹣a﹣c．
C．	a﹣b﹣d﹣c．
D．	b﹣a﹣d﹣c．

（3）What can we know about Kish from the passage？ 　　

A．	He always challenges himself bravely．
B．	He lives in fear of things that he imagines．
C．	He became blind when he was 14 years old．
D．	He broke his bone when climbing as a child．

（4）What would be the best title for the passage？ 　　

A．	How Sonar Works．
B．	Riding a Bike Using Sonar．
C．	Seeing with the Mind．
D．	How the Blind Move Around．