阅读理解。
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 footprints. Far off, he saw a very large animal standing on two legs. As
he watched, it ran very quickly.
Fifteen years later, newspapers had new stories about the "something". A mountain climber said he had seen
the "snow man" 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 (猿) man?
The mystery grew! And the mystery keeps growing. Someday we may find out just what it is that makes
the large footprints.
1. The passage is about _______. [ ]
A. some mountain climbers
B. some strange animals
C. some large footprints
D. the mystery of the Snowman
2. Why were people interested in footprints?[ ]
A. They were footprints of a large bear.
B. They looked like the footprints of a large man.
C. They were found in the snow.
D. They were found in the world's tallest mountains.
3. The pictures of large footprints were taken by a mountain climber in ________. [ ]
A. 1887
B. 1906
C. 1921
D. 1951
4. Why did the mystery grow when a mountain climber brought back pictures of large foot-prints? [ ]
A. They were footprints of an ape man.
B. They were footprints of a Snowman.
C. The pictures showed clearly how the Snowman walked.
D. The pictures showed clearly how an ape man walked on two legs.
5. Since a mountain climber first found the large footprints in the snow, the mystery of the Snowman has
puzzled the world for _______ years. [ ]
A. one hundred and fourteen
B. ninety-five
C. eighty
D. fifty
，式中α是与梁柱刚度比有关的修正系数，对底层柱：
，对一般楼层柱：
，式中，
为有关梁柱的线刚度比。
