文章大意：本文是一篇说明文。科学家们认为烟雾也可能携带和传播传染病。发表在《科学》杂志上的这一理论基于一项研究，该研究发现野火烟雾中充满了数千种微生物。其中一些微生物会引起疾病。
3 . It’s no secret that inhaling (吸入) smoke is bad for your lungs. But now, scientists are suggesting smoke may also carry and spread infectious diseases. The theory, published in Science Magazine, is based on research that found wildfire smoke is crowded with thousands of species of microorganisms. Some of these microorganisms, including bacteria and fungal spores, are known to cause disease.
The new research suggests that when a wildfire burns plant or animal matter and disturbs soils, it exposes thousands of species of bacteria and fungi that otherwise might not easily become airborne (空气传播的). You might think the high heat from fire would kill these organisms, but one study mentioned in the article found that some bacteria even multiply post-fire. Scientists say the organisms attach to smoke particles, allowing them to travel thousands of miles across continents.
Dr. Peter Chen, director of the Division of Pulmonary and Critical Care Medicine at Cedars-Sinai Medical Center in Los Angeles, is interested in the theory but somewhat skeptical that the microorganisms in smoke would actually cause infections. Many bacteria and fungi don’t cause lung infections, says Chen, but it’s certainly possible that a significant amount could worsen symptoms in someone with a preexisting lung condition. “I always thought it was the particles in smoke that were causing these issues,” says Chen. “But when I read this, I started thinking: Could it be the microorganisms that are also worsening existing illnesses?”
Whether the microorganisms in smoke actually cause infection or simply worsen potential respiratory (呼吸的) issues, the article raises a new health threat that is “certainly alarming”, says Kelsey Jack, an associate professor of environmental and development economics. This is especially true for lower-income populations, Jack says, because people with fewer means are often more exposed to the environment. If smoke is affecting the air quality in a certain area, the people who work outside, or who have to go to the office on foot or by bike will inhale more smoke than those who drive.
But until more research is done, Chen says the best thing people can do is just follow existing recommendations when air quality is poor—including staying indoors, keeping windows and doors closed, using HEPA filters and running air conditioning.
1. What can we know about the microorganisms from paragraph 2?
| A．They could be killed by high heat. |
| B．They could reproduce in large numbers after fires. |
| C．They could possibly travel through air by themselves. |
| D．They can easily attach themselves to smoke particles. |
2. How do most microorganisms affect people according to Dr. Peter Chen?
| A．They might worsen lung diseases. | B．They will cause lung infections. |
| C．They will destroy living environments. | D．They might damage respiratory systems. |
3. Why are low-income people suffering more than others?
| A．They live in poor areas. |
| B．They drive to and from work. |
| C．They have suffered from lung disease. |
| D．They are exposed to polluted air more frequently. |
4. What does the last paragraph mainly talk about?
| A．Results of the new research. |
| B．Suggestions on dealing with poor air quality. |
| C．Disagreements between the author and Chen. |
| D．Benefits of preventing smoke from polluting the air. |
