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综合写作文本
This continent of Antarctica, centered on Earth
’
s South Pole, is one of the world
’
s coldest areas,
supporting
a
very
limited
range
of
plants
and
animals.
Some
scientists
believe,
however,
that
around 15 million years ago, during the geologic period called the Middle Miocene, Antarctica
was
as
much
as
11%C
warmer
than
it
is
today,
and
it
supported
much
richer
ecosystems,
including much more diverse plant life. They have several arguments to support that claim.
Pollen Grains
First,
there
is
the
evidence
of
pollen
grains,
small
particles
that
plants
release
when
they
reproduce. Pollen grains from two types of trees dating to 15million years ago have been found
on the coast of Antarctica. Trees typically require much higher temperatures than the plants that
currently grow in Antarctica. The presence of trees indicates that the plant life in Antarctica was
much richer during the Middle Miocene, and that the temperature in Antarctica was therefore
much higher than it is today.
Carbon Dioxide
There is also some indication that carbon dioxide (CO2) levels in the atmosphere were elevated
during the Middle Miocene. Carbon dioxide is linked to climate warming because it traps heat. An
important
source
of
CO2
is
volcanic
activity.
There
were
major
volcanic
eruptions
during
the
Miocene.
That
suggests
that
atmospheric
CO2
levels
were
higher
than
they
are
today,
which
would have contributed to the warming of the Antarctic climate.
Deuterium and Increased Rainfall
Third, high levels of deuterium have been found in the remains of plants that grew in Antarctica
15 million years ago. Deuterium is a chemical element present in rainwater. Since plants absorb
deuterium
when
it
rains,
the
amount
of
deuterium
in
a
plant
usually
indicates
the
amount
of
rainfall: high levels of deuterium in the Antarctic plants from the Middle Miocene indicate high
amounts of rainfall. High amounts of rainfall are often caused by increased temperatures.
独立写作
Question:
Do you agree or disagree with the following statement?
In twenty years there will be fewer cars in use than there are today.
Use specific reasons and examples to support your answer.
36
综合写作文本
The Mary Rose was an English warship that sank in 1545 while leading an attack on the French
during the Battle of the Solent off the English coast. Several theories have sought to explain why
the Mary Rose, which had been used with great success by the English navy in several wars, sank
suddenly.
The first theory is that the Mary Rose
’
s gunports were flooded, causing the ship to sink. The Mary
Rose was one of the first ships to be equipped with gunports, or doors cut in the sides of a ship
through which heavy guns could shoot cannonballs at the enemy. Normally the gunports opened
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