Joe and David were both mountaineers．As Joe were experienced，he was always asking David to copy his example．“Want to stand on top of the world．David?” “Of course．It has already been my dream，” David answered．

On a sunny morning，the two men started for the top of Mount Qomolangma．After they climbed over one of the most dangerous slopes（斜坡），they found a man lying in the snow．“He’s going to die，” David looked at Joe and said，as if he would help the man．“Leave him alone and just follow me! But if you bring the burden（累贅）with you，I'm afraid that you'll lose your life．” Joe warned David．Then he turned around and walked forward alone．It was too cold．After thinking for a while，David made up his mind to help the man．He carried the man on his back and made his way forward．Little by little，David’s temperature made the man warm．The man came to himself! And soon he could move all by himself．Together they moved side by side．

About two hours later，they caught up with Joe．To their surprise，they found that Joe was lying in the snow，too．He had been frozen to death!

1．According to the passage，David          ．

A．was experienced                                         B．used to listen to Joe

C．died on the mountain                                   D．saved Joe

2．David and the man caught up with Joe          ．

A．as soon as the man came to himself

B．in the evening

C．about two hours later

D．after they reached the top of the mountain

3．After reading this passage，we know          

A．we must protect ourselves．

B．we can't climb Mount Qomolangma．

C．when we help others，we help ourselves．

D．we must wear warm in the snow．