阅读理解
Earthworms
don't move fast. But humans can accelerate the worms' spread. Fishermen often
use invasive(蔓延性的) earthworms to catch
fish. Many have introduced invasive earthworms to rivers, streams and lakes
previously unexposed to these animals. Gardeners who use earthworms to make
their soil rich may unknowingly introduce invasive ones. The worms even give
rides in the mud on wheels, potted plants and road materials shipped around the
nation.
But
they're not everywhere yet. In the Great Lakes region, "20 percent of the
land is earthworm-free," says Cindy Hale, a research biologist. Of the
remaining 80 percent of land, half of the land has fewer than two earthworm
species-meaning there isn't yet too much impact on the ecosystem, she explains.
For these regions, she says, now is the time to take action. According to Hale,
educating the public, especially fishermen, is one approach to stopping the
spread of invasive earthworms. Identifying which lands are currently
earthworm-free is another.
Ryan
Huefimeier, a program coordinator for Great Lakes Wom Watch, has been working
on a model that will help create large maps of areas with minimal(最小的) or no damage from earthworms. Ultimately, landowners can use it to
identify earthworm activity on their property. once identified, lands with
minimal or no earthworm damage should be protected.
But
scientists suspect that once invasive earthworms arrive they can't be removed.
And even if all could be, affected forests might never return to the way they
were. "It's very much a story of learning to live with them,"
concludes Lee Frelich of the University of Minnesota's Center for Forest
Ecology.
Forest
ecologists have called earthworms "ecosystem engineers" because they
can change or create habitats that otherwise would not be present. Whether this
is a good thing depends on the situation.
"What
the earthworms do and how we value it is what really matters." said Hale. "In
one place-farm fields or gardens-we really like European earthworms and what
they do, so we consider them good. In native hardwood forests, we really don't
like what they do-so we consider them bad. You really have to understand how an
organism(微生物) affects an ecosystem.
Things aren't black and white."
(1)
Why are fishermen and gardeners mentioned in the first paragraph?
A . To attract more people to fishing and gardening.
B . To introduce different uses of invasive earthworms.
C . To stress the importance of invasive earthworms to humans.
D . To show humans' effect on the spread of invasive earthworms.
(2)
What is Hale's advice on protecting the Great Lakes region from invasive earthworms?
A . Finding out areas free of earthworms.
B . Extending a ban on the fishing industry.
C . Making maps of areas with most earthworms.
D . Informing the public of different earthworm species.
(3)
What is Hale's attitude towards invasive earthworms?
A . Objective.
B . Positive.
C . Ambiguous.
D . Doubtful.
(4)
Where is the text probably from?
A . A biology textbook.
B . An official report.
C . A science magazine.
D . A research paper.
答案: D
A
A
C