Упражнения уровня TOEFL по английскому языку. № 46.

Two hundred million years ago, forests covered the land on earth, the atmosphere had a lot of carbon dioxide, the air was 10 degrees Celsius warmer than now and the oceans were 230 feet higher. Gradually, processes involving photosynthesis and phytoplankton captured carbon and other greenhouse gases from the air and laid them down in the crust of the earth, much of it in the form of methane, coal, gas and oil. This reduced the concentration of greenhouse gases, the earth cooled and water levels fell. For the last 200 years we have been reversing the process, putting carbon and other elements back into the atmosphere. Scientists have known about this for a long time. The influence on climate of the various gases in the atmosphere was first identified in 1827 by Joseph Fourier, a French mathematician.

(1) The passage suggests that…
a) the earth's climate is stable. /
b) scientists have been irresponsible. /
c) greenhouse gases affect the earth's climate. /

(2) The passage states that…
a) climate change is a gradual process. /
b) the earth is running out of coal, gas and oil. /
c) pollution has become a problem in the last 200 years. /

(3) Choose the most appropriate title for the passage:
a) Global Heating: An Overview. /
b) Global Warming: A Historic Perspective. /
c) Fossil Fuels and Their By-Products. /