[单项选择]

The sun shines because it is made of glowing gases. It gives off its own light. The moon shines too, but it doesn’t give off any light of its own. We can see the moon only because it reflects light from the sun. The moon travels around the earth about every twenty-nine days. During this time, the moon looks as if it changes size and shape. It seems to grow from a small part of a shining circle into a full circle. Then it becomes small again. The moon doesn’t really change. It is just because we see different parts of it lit up by the sun.

The moon seems to change size and shape because ______.[A] it gives off different amounts of light[B] part of it bums up[C] we see different parts of it

[单项选择]The sun shines because it ______.

[单项选择]The sun shines because it is made of glowing gases. It gives off its own light. The moon shines too, but it doesn’t give off any light of its own. We can see the moon only because it reflects light from the sun.
The moon travels around the earth about every twenty-nine days. During this time, the moon looks as if it changes size and shape. It seems to grow from a small part of a shining circle into a full circle. Then it becomes small again. The moon doesn’t really change. It is just because we see different parts of it lit up by the sun.

The sun shines because it ______.
A. gets light from the moon
B. is made of glowing gases
C. travels around the earth

[单项选择]I'd like to live somewhere （　） the sun shines all year long,
A. which
B. that
C. where
D. in which

[单项选择]I'd like to live somewhere（）the sun shines all year long.
A. which
B. that
C. where
D. in which

[填空题]The longer the sun shines, (warm) _____ the earth is.

[填空题]Natural gas is mainly made up of methane and other hydrocarbon gases.

[简答题]As time went on, hot sun and cool rains made the rock split and break into pieces, sea waves dashed against the rock.

[单项选择]Natural Gas Natural gas is produced from reservoirs deep beneath the earth’s surface. It is a fossil fuel, meaning that it is derived from organic material buried in the earth millions of years ago. The main component of natural gas is methane. The popularity and use of clean natural gas has increased dramatically over the past 50 years as pipeline infrastructure has been installed to deliver it conveniently and economically to millions of residential, commercial and industrial customers worldwide. Today, natural gas service is available in all 50 states, and is the leading energy choice for fueling American homes and industries. More than 65 million American homes use natural gas. In fact, natural gas is the most economical source for home energy needs, costing one-third as much as electricity. In addition to heating homes, much of the gas used in the United States is used as a raw material to manufacture a wide variety of products, from paint, to fibers for clothing, to plastics f

[填空题]A Popularity and use of natural gas
B Natural gas reserves and supply
C Natural gas prices
D Clean fuel of choice
E Disadvantages of natural gas
F Natural gas consumption
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