(B)
When John Todd was a child,
he loved to explore the woods around his house, observing how nature solved
problems. A dirty stream, for example, often became clear after flowing through
plants and along rocks where tiny creatures lived. When he got older, John
started to wonder if this process could be used to clean up the messes people
were making.
After studying agriculture, medicine, and fisheries in college,
John went back to observing nature and asking questions. Why can certain plants
trap harmful bacteria (细菌)? Which kinds of fish can eat cancer-causing
chemicals? With the right combination of animals and plants, he figured, maybe
he could clean up waste the way nature did. He decided to build what he would
later call an eco-machine.
The task John set for himself was to remove
harmful substances from some sludge (污泥). First, he constructed a series of clear
fiberglass tanks connected to each other. Then he went around to local ponds
and streams and brought back some plants and animals. He placed them in the
tanks and waited. Little by little, these different kinds of life got used to
one another and formed their own ecosystem. After a few weeks, John added the
sludge.
He was amazed at the results. The plants and animals in the
eco-machine took the sludge as food and began to eat it! Within weeks
it had all been digested, and all that was
left was pure water.
Over the years, John has taken on many big jobs. He developed a
greenhouse — like facility that treated sewage (污水) from 1,600 homes in South Burlington. He also
designed an eco-machine to clean canal water in Fuzhou, a city in southeast
China.
“Ecological design” is the name John gives to what he does. “Life
on Earth is kind of a box of spare parts for the inventor,” he says. “You put
organisms in new relationships and observe what’s happening. Then you let these
new systems develop their own ways to self-repair.”
4. What can we learn about John from the first two paragraphs?
A. He was fond of traveling.
B. He enjoyed being alone.
C. He had an inquiring mind.
D. He longed to be a doctor.
5. Why did John put the sludge into the tanks?
A. To feed the animals.
B. To build an ecosystem.
C. To protect the plants.
D. To test the eco-machine.
6. What is the author’s purpose in mentioning Fuzhou?
A. To review John’s research plans.
B. To show an application of
John’s idea.
C. To compare John’s different
jobs.
D. To erase doubts about John’s invention.
7. What is the basis for John’s work?
A. Nature can repair itself.
B. Organisms need water to survive.
C. Life on Earth is diverse.
D. Most tiny creatures live in groups.
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