VOA慢速：研究发现细菌有助于减少“温室气体”排放
Researchers: Bacteria Could Help Reduce ‘Greenhouse’ Gas
慢速| 考研偏难| 603词| 5min45s
刘立军供稿
Part I. QUESTIONS
Listen to the news and choose the best answer to each question you hear.
Q1. What did tests in the laboratory and in the field show about the bacteria?
A. It reduced nitrous oxide.
B. It increased soil fertility.
C. It harmed other microbes.
D. It was genetically modified.
Q2. What did robots measure during the field tests conducted by Bakken and other researchers?
A. Soil pH levels.
B. Bacteria growth rates.
C. Nitrous oxide emissions.
D. Crop yields.
Q3. Why does Paul Carini believe using the bacteria is cost-effective?
A. It reduces the need for chemical fertilizers.
B. It increases crop yields significantly.
C. It helps in producing biofuels efficiently.
D. It utilizes waste products from another industry.
Q4. What is the challenge mentioned by Bakken regarding the widespread adoption of bacteria to reduce nitrous oxide emissions?
A. The bacteria are expensive to produce and distribute.
B. Farmers currently have no financial incentives to reduce nitrous oxide emissions.
C. The bacteria have not been proven effective in any field conditions.
D. The bacteria are genetically modified and face regulatory hurdles.
Q5. What is the primary focus of the research study mentioned in the text?
A. The environmental impact of fertilizers.
B. The discovery of new bacteria species.
C. A method to reduce nitrous oxide emissions using bacteria.
D. The economic feasibility of biofuels.
Part II. TRANSCRIPT
Researchers: Bacteria Could Help Reduce ‘Greenhouse’ Gas
Very small organisms that live in the world’s farm fields release nitrous oxide gas.
nitrous oxide 氧化亚氮，笑气
Some scientists link the gas to climate change. They are looking for a way to deal with the issue.
Now, some researchers think they have found bacteria that can help reduce the amount of nitrous oxide released. (Q1) In a recent publication of Nature, scientists said tests in the laboratory and in the field showed that one kind of bacteria reduced nitrous oxide without hurting other microbes in the soil. The bacteria also survived well in soil and would not be very costly to produce.
microbe n. 微生物
Lars Bakken is with the Norwegian University of Life Sciences. He was one of the writers of the study. Bakken said, “It opens up a number of new possibilities in bioengineering of the farmed soil.”
bioengineering n. 生物工程
The Associated Press reports that nitrous oxide can warm the atmosphere 265 times more than an equal amount of carbon dioxide. Nitrous oxide can remain in the atmosphere for more than a hundred years.
Farmers’ use of nitrogen fertilizer drives up the amount of nitrous oxide produced in soil.
The U.S. Environmental Protection Agency said that, in 2022, nitrous oxide made up six percent of all U.S. greenhouse gas emissions from human activities.
That is a big problem in agriculture, said Lori Hoagland of Purdue University in the state of Indiana. Hoagland was not involved in the recent study.
She described the plan to reduce nitrous oxide as “really interesting.”
How the work was done
Bakken and other researchers used organic waste to grow their bacteria. Building on past work, the researchers looked for a microorganism that would last long enough to reduce nitrous oxide emissions without staying in the soil so long that it hurt other life forms that are important for crop health.
microorganism n. 微生物
(Q2) In field tests, the researchers used robots to measure nitrous oxide emissions during the day and during the night.
They compared conditions in soil with and without the bacteria. Researchers found the bacteria reduced the nitrous oxide emissions of the first fertilizer treatment by 94 percent.
Two weeks later, the bacteria reduced the emissions of a second fertilizer treatment by about half. After about three months, there was no difference in the makeup of microbial life forms. This suggested to the researchers that their bacteria would not change or hurt the soil.
The bacteria that researchers used is found naturally in anaerobic digesters, machines that are already being used to turn organic waste products like cow manure into biofuels. The researchers said the bacteria are not genetically modified. That might ease acceptance of their use, said Paul Carini of the University of Arizona.
anaerobic adj. 厌氧的，无氧的
manure n. 粪肥；肥料
biofuel n. 生物燃料
Carini was also not involved in the research.
Bakken said the bacteria could be included in some fertilizers on farms in three to four years if people think it is worth the cost.
Carini thinks using the bacteria is worth it.
(Q3) “Any time you’re using a waste product from one industry to benefit another industry, that’s pretty cost-effective,” he said.
cost-effective adj. 有成本效益的，划算的
(Q4) However, Bakken pointed out that farmers are not paid for reducing nitrous oxide emissions. He thinks there must be additional incentives for emissions reductions. “The task for the authorities is to install policy instruments that makes it profitable in one way or another,” he said.
nitrous adj. 氮的，含氮的
Hoagland, the Purdue professor, said more research in field conditions would likely be needed before the bacteria could be used worldwide. That is because soil is different in places around the world.
“If they can get this to work across soils, it would just have a tremendous impact, for sure,” she said.
Part III. KEY
Q1. A. 细节题。出处：“… tests in the laboratory and in the field showed that one kind of bacteria reduced nitrous oxide without hurting other microbes in the soil.”意为：“……实验室和实地的测试表明，这种细菌减少了氧化亚氮的释放，且没有给土壤中其他微生物造成伤害。”因此答案是A。
Q2. C. 细节题。出处：“In field tests, the researchers used robots to measure nitrous oxide emissions during the day and during the night.”意为：“在实地试验中，研究人员使用机器人在白天和晚上测量氧化亚氮的排放量。”因此答案是C。
Q3. D. 推理题。出处：“Any time you’re using a waste product from one industry to benefit another industry, that’s pretty cost-effective,”意为：“任何时候，当你利用一个行业的废弃产品来作为另一个行业的资源时，这都是相当经济有效的。”因此答案是D。
Q4. B. 推理题。出处：“Bakken pointed out that farmers are not paid for reducing nitrous oxide emissions. He thinks there must be additional incentives for emissions reductions.” Bakken指出，农民目前没有减少氧化亚氮排放的经济激励，建议需要政策激励。因此答案是B。
Q5. C. 主旨题。文章主要讨论了一种新发现的利用细菌来帮助减少氧化亚氮排放的方法，因此答案是C。
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