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.”

1.1. 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.

解析：选C。推理判断题。根据前两段中的“When John Todd was a child, he loved to explore the woods around his house, observing how nature solved problems.”（当约翰·托德还是个孩子的时候，他喜欢探索房子周围的树林，观察大自然是如何解决问题的）以及“After studying agriculture, medicine, and fisheries in college, John went back to observing nature and asking questions. ”（在大学学习了农业、医学和渔业之后，约翰又回到了观察自然和提出问题的生活中）下文还列举了他思考的各种各样的问题，由此可知，约翰·托德极有好奇心，且善于思考，C项 He had an inquiring mind.他爱刨根问底。故选C。

2.2. 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.

解析：选D。推理判断题。根据题干中的sludge把关键信息定位在第三四段。根据第三段第一句“The task John set for himself was to remove harmful substances from some sludge. ”（约翰给自己定的任务是从污泥中去除有害物质）。接下来的“First... Then...He placed...”在一系列的操作之后，“Little by little, these different kinds of life got used to one another and formed their own ecosystem.”(渐渐地，这些不同种类的生命相互适应，形成了自己的生态系统) 然后“After a few weeks, John added the sludge.”(几个星期后，约翰把污泥加了进去)。结果令人惊讶，“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.”(生态机器里的动植物把污泥当成了食物，开始吃起来!几周之内，它就被消化了，只剩下纯净水。)由此可知，加入污泥是为了检验生态机器是不是在清洁污泥方面起作用。D项To test the eco-machine.测试生态机器。故选D。

3.3. 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.

解析：选B。推理判断题。根据题干中的Fuzhou，把关键信息定位在第五段。第五段最后一句“He also designed an eco-machine to clean canal water in Fuzhou, a city in southeast China.”他还设计了一种生态机器来清洁中国东南部城市福州的运河水。由此可知，这是约翰·托德所设计的生态机器的一个实际应用，B项To show an application of John’s idea.展示约翰想法的应用。故选B。

4.4. 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.

解析：选A。推理判断题。从文章最后一段最后两句“You put organisms in new relationships and observe what’s happening. Then you let these new systems develop their own ways to self-repair.”(把生物体放在新的关系中，观察会发生什么。然后让这些新系统自行发展自我修复的方式)可知，约翰·托德的研究依据是生态系统具有自我修复的能力。A项Nature can repair itself. 大自然可以自我修复。故选A。