C．阅读短文，然后回答短文后面的问题。（7．5分）
Is there something strange high up in the world s tallest mountains？If so，is it a big bear？ Is it a monkey？Or is it a kind of man？
No one knows．This mystery（谜）has puzzled（困惑）the world for years．
In 1887，a mountain climber found large footprints（脚印）in the snow．They looked like the footprints of a very large man．But men don t walk without shoes in the snow！
In 1906，another climber saw more than footprints．Far off，he saw a very large animal standing on two legs．As he watched，it ran very quickly．
Fifteen years later，newspaper had new stories about the“something”．A mountain climber said he had seen the“Snowman”walk slowly across the snow，far below him．He said it looked like a very large man．
From then on，more and more people had stories to tell．But not until 1951 did a mountain climber bring back pictures of large footprints．“The pictures showed clearly that the Snowman walked on two legs．”So it was not a bear or a monkey．Could it be an ape（类人猿） man？The mystery grew！And the mystery keeps growing．Some day we may find out what it is that makes the large footprints．
1．What s the passage about？________
2．Why were people interested in the footprints？________
3．When were the pictures of large footprints taken by a mountain climber？________
4．Why did the mystery grow when a mountain climber brought back pictures of large footprints？________
5．How long has the mystery of the Snowman puzzled the world since a m ountain climber first found the large footprints in the snow？________
Key:
C．1．It s about the mystery of the Snowman．
2．Because they looked like the footprints of a large man．
3．1951．
4．Because the pictures showed clearly that the Snowman walked on two legs．
5．One hundred and fifteen years．