READ THE FOLLOWING PASSAGE CAREFULLY AND ANSWER THE QUESTIONS THAT FOLLOW BY CIRCLING LETTER A, B, C OR D AS THE CORRECT ANSWERS AND THEN MARK YOUR CHOICE ON THE ANSWER SHEET
QUESTIONS 36 - 40: Read the following passage carefully and answer the questions that follow by circling letter
A, B, C or D as the correct answers and then mark your choice on the answer sheet.
A greenhouse is a building whose sides and roof are made of glass so that the temperature inside is magnified. And it's
used to grow plants that need high temperatures. This is to illustrate an example of how man could be causing changes
to the climate. These changes result from increasing the carbon dioxide levels in the atmosphere, thus raising the surface
temperature of the Earth. And this is known as the "Greenhouse Effect."
C0
2
is a normal component of the atmosphere and until recently has not been considered an air pollutant. But average
global CO
2
concentrations have been increasing since 1860, with particularly sharp increase in 1958. The main reason
for this continuous increase in C0
2
build-up is the burning of fossil fuels. During the past 100 years, the C0
2
content of
the atmosphere has already risen by about 15% - from about 290 to about 340 parts per million. And it's still rising.
Although the C0
2
content of the atmosphere is only about 0.032%, it's a major factor in determining average global
temperature. Incoming sunlight consists of many wavelengths including some very dangerous ones. But ozone in the
upper atmosphere and water vapor and C0
2
in the lower atmosphere filter out or destroy most of the harmful
wavelengths, so what reaches the
Earth is mostly visible light. It's absorbed by land, sea and cloud and is reradiated in the atmosphere as longer
wavelength infrared radiation, or heat, as the Earth cools. Much of this infrared radiation is absorbed by C0
2
. The C0
2
then radiates a portion of the absorbed heat energy back to the Earth to warm the atmosphere. Rather like the glass in a
greenhouse or a car window
on sunny day, C0
2
in the atmosphere acts as a one-way filter that allows visible light to enter the Earth's atmosphere, but
prevents longer wavelength heat radiation from leaving. Assuming that energy is arriving from the sun at a constant
rate, then as the level of C0
2
increases, the average surface temperature of the earth should rise.
36. What is the purpose of using a greenhouse?
A. to give an example of atmospheric changes caused by man
B. to magnify temperature to grow plants requiring high temperatures
C. to give an example of buildings whose sides and roof are made of glass
D. to indicate the rising level of C0
2
in the earth's atmosphere
37. What is mainly discussed in paragraph 1?
A. The sides and roof of a greenhouse are made of glass B. Plants need high temperatures to grow
C. What is the "Greenhouse Effect"?
D. A greenhouse is used for growing plants
38. Why is C0
2
considered an air pollutant?
A. C0
2
is a normal component of the atmosphere
B. Global C0
2
concentrations have been increasing
C. C0
2
is a by-product of the burning of fossil fuels
D. C0
2
raises the surface temperature of the Earth
39. What is not true according to the information from the passage?
A. The level of C0
2
has risen by as much as 15%
B. The sun emits some very dangerous wavelengths
C. A portion of sunlight is filtered out before entering the Earth
D. C0
2
allows sunlight to enter and leave the Earth's atmosphere
40. What is the best title for the passage?
A. The "Greenhouse Effect" and how C0
2
warms the atmosphere
B. The level of C0
2
at present compared with that in the past
C. Ozone and water vapor with filtering out harmful wavelengths
D. The "Greenhouse Effect" used for growing plants