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Questions 36 to 40 are based on the
following passage:
Carbon dioxide makes up less than one
percent of the Earth's atmosphere. But the gas is very important to life on
Earth. Scientists are finding that processes involving carbon dioxide affect
our climate in ways that are difficult to understand. Last month, a committee of the National
Academy of Sciences in Washington released a report. It confirmed that world
temperatures increased about six-tenths of a degree Celsius in the last one
hundred years. The report also confirmed evidence that the level of carbon
dioxide is increasing.
The best information about climate in the
past comes from tests of ice many kilometers deep in Antarctica and Greenland.
The tests show changes in temperature during the past four-hundred-thousand
years. These tests show that levels of carbon dioxide today are the highest
ever measured. These findings have led scientists to believe that carbon
dioxide is a major cause of climate warming.
Carbon dioxide is released into the
atmosphere when fuel is burned. Oil, coal and wood are all fuels that release
the gas. When biological waste breaks down, it also releases carbon dioxide.
However, plants use carbon dioxide in the
process called photosynthesis. This process provides food for almost all life
on Earth. Some groups that support burning oil and coal want to increase the
amount of carbon dioxide in the atmosphere. They oppose international efforts
to control carbon dioxide.
Some scientists believe that forests and
trees are able to capture large amounts of carbon dioxide from the air. Some
groups even suggest that an increase in carbon dioxide could cause plants to
grow faster.
A recent study in North Carolina found that
more carbon dioxide in the air could cause trees to grow faster. But the
researchers found the effect appears to last for only three years. Another
study showed that much of the carbon dioxide that is taken in by trees is
released within three years. The study noted that leaves release carbon dioxide
when they fall from trees and break down in the soil. Plants also naturally
release carbon dioxide through the process of respiration.
The natural balance of gases in the
atmosphere is a complex scientific issue. The debate over carbon dioxide is
only one part of efforts to understand world climate change.
36.Which one is NOT mentioned in this
passage that can be the source of carbon dioxide?A) Oil. B) Trees. C) Wood. D) Soil.
37.The committee report of National Academy
of Sciences in Washington reveal that____.
A) ice from Antarctica and Greenland is
appropriate to show the change
B) carbon dioxide is released mainly from
the fuel
C) level of carbon dioxide increases with
global temperatures
D) carbon dioxide is helpful for tree
growth
38.According to this passage, those people
disagree with the control of carbon dioxide because____.
A) they think that carbon is beneficial for
plant growth
B) they want to use more fuels that can
emit carbon dioxide
C) they think carbon dioxide is not the
main reason for global warming
D) they think it will destroy the natural
balance of gases in the world
39.The word "issue" in the last
paragraph can be replaced as ____.
A) organ B) topic C) publication D)
result
40.Those studies carried out in North
Carolina suggest that ____.
A) trees' function for absorbing carbon
dioxide is limited
B) carbon dioxide is the main cause for
global warming
C) leaves falling from trees can emit more
oxygen
D) more carbon dioxide is beneficial for
trees' growth for many decades
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