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Some of the most beautiful caves are formed in glaciers (冰川). Streams of melting ice and snow tunnel through the glaciers the same way that water from a faucet melts its way through an ice cube. Water from the surface drips down through cracks, hollowing out the tunnels and decorating the caves with crystal icicles. The smooth walls and floors are so glasslike that pebbles frozen six feet deep can easily be seen. Crystal-clear icicles draping from the ceilings flash blue green, as though they were carved from precious jewels instead of ice.
Although most of the cave ice in the United States is found in lave caves, there are a number of limestone ice caves as well. Some people .believe that this ice was formed thousands of years ago, when temperatures were much colder than they are today. Others think that the cave ice broke off from the ancient glaciers as they spread over the country.
Today many cave scientists have another idea. They believe that cold water sinks down through cracks into these caves until temperature is chilly enough to freeze the water that seeps (渗入) in. The ice that keeps the cave cool, and that helps build up still more ice. Many caves become covered with so much ice that no one knows just how thick it is. In some, such as crystal Falls Cave in Idaho, there are frozen rivers and even frozen waterfalls. Native Americans and early settlers used to store food in these underground refrigerators and chip out blocks of ice to melt for drinking water.
1. What is the main idea about this passage?
A. Characteristics of glaciers. B. Uses for ice caves.
C. The origin of cave ice. D. Where glaciers can be found.
2. What causes ice to build up in caves?
A. Rivers and waterfalls water.
B. Icicles accumulate on the ceilings.
C. Cave ice breaks off glaciers.
D. Cold water seeps in and freezes.
3. It can be inferred from the passage that the early settlers appreciated the ice caves for their——.
A. practicality B. beautiful interiors
C. historical value D. precious jewels
4. The author compares icicles to precious jewels based on which of the following?
A. appearance B. cost
C. method of formation D. availability
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Have you ever wondered what you will be when you grow up? Perhaps you have thought of becoming an engineer or an environmentalist. Here’s good news: you can combine all of these career goals by designing, building and operating a solar-powered house.
That is what students from 20 universities did as they competed in the U.S. Department of Energy 2009 Solar Decathlon (十项全能). Like a game show where teams compete against each other, the Solar Decathlon’s student teams competed against each other in ten separate events to see who could build the best solar-powered house. The team from Germany took the top honor.
The contest is held on the National Mall in Washington D.C., and is open to the public. In order to win, the Decathlon’s teams have to successfully host a dinner party, do the laundry, run the dishwasher, and maintain a comfortable temperature in their solar-powered houses. They also have to make their houses look attractive. Team Germany’s winning "Cube House" produced a surplus (剩余) of power, even during three days of rain. This is the fourth time the Solar Decathlon has been held. The houses keep getting better and better.
"The Department of Energy does research on solar and building technologies. In the 1990s, we were seeking expertise to help design houses that would integrate (合并) solar systems in a reliable way. I came up with the idea of having a competition to challenge students at architecture and engineering schools to design solar-powered houses from the ground up. I thought that having a competition would motivate these students to be creative. The new generation of our country should be innovative (创新的). They may come up with solutions that would help our country," said Richard J. King, the Decathlon’s Director.
63. The first paragraph serves as a(n) ________.A. explanation B. conclusion C. background D. introduction
64. Which of the following should the Decathlon’s teams consider during the competition?
a. the appearance of the house
b. the power supply of the house
c. housework management
d. the design of solar-powered kitchenware A. abd B. abc C. bcd D. acd
65. Richard came up with the idea of having a competition mainly to ________.
A. raise funds to design solar-powered buildings
B. motivate students to be creative
C. integrate solar systems with buildingsD. develop new kinds of energy
66. What do we know about the Solar Decathlon from the text?
A. The participated teams are separated from the outside world during the competition.
B. The house designed by the German team will be adopted by the Department of Energy.
C. The competition had been held three times before 2009.
D. It includes students from twenty countries around the world.
Many times a reporter needs works that describe how something looks．Then he uses special words．And so it is with mathematics．The words square and rectangle are special words in mathematics．
A square has four sides and four square corners．But all four sides of a square are the same in length．
A rectangle also has four sides and four square corners．Two sides of a rectangle are usually longer than the other two sides．
Two more special words used in mathematics are triangle and circle．A triangle has only three sides and three corners．A triangle is like the top of a roof that comes to a point．The space at any corner．A triangle is like the top of a roof the comes to a point．The space at any corner between two sides in a triangle is called an angle．If all the three sides of a triangle are equal, then all the three angles would be equal too．Such a kind of triangle is called an equilateral triangle．
A circle has no sides at all．It is a closed pane curve（弧线）consisting of all points equally distant from a point within it, called the center．A circle is like the face of a coin．Some times a person says a thing is “circular”．Do you think you know what he means?
In geometry we also have words like cube, sphere, cylinder, cone and so on．They are all three dimensional（三维的）．But we are not going to deal with them here．
1．Sometimes a person says that something is circular, he means this something is ______．
[ ]
A．a circle
B．like a circle
C．round in shape
D．curved in shape
2．Which of the following is not necessarily true? A closed plane curve is ______． [ ]
A．a space enclosed by a curved line
B．a curve
C．two-dimensional
D．a circle
3．Which of the following is equilateral?______．
[ ]
A．triangle B．Square
C．Circle D．Rectangle
4．Which of the following does not have an angle of 90 degree?______．
[ ]
A．a right angled triangle
B．A square
C．A rectangle
D．A circle
5．Which of the following statements is true of a curve?______．
[ ]
A．No part of which is straight
B．It changes direction without angle
C．It is always closed
D．It is continuously bending line
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Although most of the cave ice in the United States is found in lave caves, there are a number of limestone ice caves as well. Some people .believe that this ice was formed thousands of years ago, when temperatures were much colder than they are today. Others think that the cave ice broke off from the ancient glaciers as they spread over the country.
Today many cave scientists have another idea. They believe that cold water sinks down through cracks into these caves until temperature is chilly enough to freeze the water that seeps (渗入) in. The ice that keeps the cave cool, and that helps build up still more ice. Many caves become covered with so much ice that no one knows just how thick it is. In some, such as crystal Falls Cave in Idaho, there are frozen rivers and even frozen waterfalls. Native Americans and early settlers used to store food in these underground refrigerators and chip out blocks of ice to melt for drinking water.
1. What is the main idea about this passage?
A. Characteristics of glaciers. B. Uses for ice caves.
C. The origin of cave ice. D. Where glaciers can be found.
2. What causes ice to build up in caves?
A. Rivers and waterfalls water.
B. Icicles accumulate on the ceilings.
C. Cave ice breaks off glaciers.
D. Cold water seeps in and freezes.
3. It can be inferred from the passage that the early settlers appreciated the ice caves for their——.
A. practicality B. beautiful interiors
C. historical value D. precious jewels
4. The author compares icicles to precious jewels based on which of the following?
A. appearance B. cost
C. method of formation D. availability
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