填空题

Scientists claim that air pollution causes a decline in the
world’s average air temperature. In order to prove that theory,
ecologists have turned to historic data in relation to especially (1) ______
huge volcanic eruptions. They suspect that volcanoes influence
weather changes that are similar with air pollution. (2) ______
One source of information is the affect of the eruption of (3) ______
Tambora, a volcano in Sumbawa, the Dutch East Indies, in
April 1815. The largest recorded volcanic eruption, Tambora
threw 150 million tons of fine ash into the stratosphere. The
ash from a volcano spreads worldwide in a few clays and remain (4) ______
in the air for years. Its effect is to turn incoming solar
radiation into space and however cool the earth. For example, (5) ______
records of weather in England show between April and
November 1815, the average temperature has fallen 4.5F. (6) ______
During the next 24 months, England suffered one of the cold (7) ______
periods of its history. Farmer’s records from April 1815 to
December 1818 indicate frost throughout the spring and summer
and sharp decreases in crop and livestock markets. Since there
was a time lag of several years between reason and effect, by (8) ______
the time the world agricultural commodity has deteriorated,
no one realized the cause.
Ecologists today warn that we face with a twofold menace. (9) ______
The ever-present possibility of volcanic eruptions, such as
that of Mt. St. Helens in Washington, added to man’s pollution
of the atmosphere with oil, gas, coal, and other polluting
substances, may bring us increasing colder weather. (10) ______