Part A: Reading Comprehension

Directions: Read the following text. Answer the questions below each text by choosing A, B, C or D. Mark your answers on the ANSWER SHEET. (40 points)

Text 4

When Tom Swetnam joined the U.S. Forest Service in the 1970s, his mandate was to “put everything out,” he recalled. But when Swetnam enrolled in graduate school at the University of Arizona’s Laboratory of Tree-Ring Research, he was surprised to find a record of repeated blazes dating back hundreds of years before European colonists arrived on the continent. Some of the trees he analyzed bore more than 20 fire scars among their rings.

The fact that fires happened so often meant they couldn’t have been severe enough to kill most trees. Instead, a growing body of research showed that frequent, low-severity fires made many ecosystems healthier. They rid the forest of dead and sick trees, reducing competition and curbing the spread of disease. Because flammable material couldn’t build up on the landscape, blazes tended to move slowly and peter out when they reached the footprints of previous burns.

In 2022, Swetnam and other scientists teamed up to compile a database of fire-scarred trees from across the continent. Their North American tree-ring fire-scar network (NAFSN) provided the basis for a study published last month. In the study, the researchers compared the historical fire cadence with the wildfires recorded over the past few decades, and uncovered a striking shortfall. The NAFSN sites experienced less than a quarter of the number of fires that would have been expected without fire suppression.

This deficit is a testament to the effectiveness of modern firefighting, said Kelly Martin, a past president of the International Association of Wildland Fire. “Yet the combined consequences of suppression and climate change have eroded humanity’s ability to suppress fires, particularly those that ignite under the most dangerous weather conditions.”

To prevent entire ecosystems from going up in smoke, Martin said, people must bring healthy fire back to the places that need it. At Yosemite National Park, Martin oversaw the use of what are known as prescribed burns to make the landscape more resilient. These fires were carefully planned and intentionally ignited during periods when weather kept the blazes easy to control, and helped eliminate some of the fuel that had built up around important park’s facilities. Research shows that these prescribed burns make subsequent wildfires less severe, even if later fires happen under the most dangerous weather conditions.

Yet even as scientists and public officials increasingly agree on the need for more fires in our forests, climate change is making this tactic more challenging, experts said. “It’s a double-edged sword because wildfires are getting more severe and larger under climate change and we need this work even more, but then the work gets more challenging,” said Susan Prichard, a fire ecologist at the University of Washington.

36. According to Paragraph 1, Swetnam was surprised by

the scarcity of tree-ring research in the U.S.

the firefighting measures in ancient Europe.

the forest management practices in the 1970s.

the number of wildfires in precolonial times.

37. Paragraph 2 mainly focuses on

the causes of previous burns.

the treatment of diseased trees.

the benefits of low-severity fires.

the importance of forest ecosystems.

38. What did the study find about the wildfires over the past few decades?

Their intensity has vastly fluctuated.

Their frequency has markedly decreased.

Their threats have been underestimated.

Their records have been misinterpreted.

39. What can be inferred about modern firefighting?

Its workforce needs more training.

Its effectiveness is questioned by the public.

It may render traditional tactics useless.

It may make severe fires harder to put out.

40. Both Martin and Prichard would agree that

it is challenging to predict large wildfires.

it is urgent to assess the use of planned fires.

it is necessary to introduce prescribed burns.

it is rewarding to double fire detection efforts.

答案与解析 (Answers)

36. [D] the number of wildfires in precolonial times.
解析：第一段指出 Swetnam 在研究生期间惊讶地发现，早在欧洲殖民者到达之前，就有数百年前的重复火灾记录（record of repeated blazes dating back hundreds of years before European colonists...）。他分析的一些树木年轮中有超过20处火疤，说明火灾非常频繁。这对应了 D 选项“前殖民时代的野火数量”。

37. [C] the benefits of low-severity fires.
解析：第二段详细阐述了频繁、低强度的火灾如何使生态系统更健康（made many ecosystems healthier）：清理病死树、减少竞争、抑制疾病传播、防止可燃物堆积。整个段落都在论述这种火灾带来的“益处（benefits）”，选 C。

38. [B] Their frequency has markedly decreased.
解析：第三段提到研究人员发现了一个“惊人的缺口（striking shortfall）”：过去几十年的火灾数量不到在没有人工干预情况下预期数量的四分之一（experienced less than a quarter of the number...）。这说明火灾发生的频率显著降低了，选 B。

39. [D] It may make severe fires harder to put out.
解析：根据第四段，长期的灭火（suppression）导致森林中燃料（可燃物）堆积，加上气候变化的影响，削弱了人类扑灭最危险天气条件下爆发的火灾的能力（eroded humanity’s ability to suppress fires）。这意味着现代消防政策反而可能使严重的火灾更难扑灭，选 D。

40. [C] it is necessary to introduce prescribed burns.
解析：第五段中 Martin 主张必须将健康的火（即 prescribed burns 计划烧除）带回森林。第六段中 Prichard 指出虽然由于气候变化这项工作变得更具挑战性，但“我们甚至更需要这项工作（need this work even more）”。因此，两人都同意引入计划烧除的必要性，选 C。

核心长难句精解 (Highlighted Sentences)

1. 过去分词短语作定语与时间状语从句：
"But when Swetnam enrolled in graduate school..., he was surprised to find a record of repeated blazes dating back hundreds of years before European colonists arrived on the continent."
 【解析】dating back to... 是现在分词短语作后置定语，修饰 record。before... 引导时间状语从句。这句话点明了本文的核心发现：自然状态下的火灾频率远超人类想象。 
【翻译】但当斯威特纳姆进入研究生院时……他惊讶地发现了一项重复火灾的记录，这些记录可以追溯到欧洲殖民者到达美洲大陆之前的数百年。 
2. 原因状语从句与并列谓语：
"Because flammable material couldn’t build up on the landscape, blazes tended to move slowly and peter out when they reached the footprints of previous burns."
 【解析】Because 引导原因状语从句。主句中 tended to 后面接了两个并列的动词短语 move slowly 和 peter out（逐渐消失）。这句话解释了低强度火灾不具备毁灭性的机制。 
【翻译】因为易燃物质无法在景观中堆积，所以烈火往往移动缓慢，并且在到达之前烧毁区域的足迹时便会逐渐熄灭。 
3. 让步状语从句与双刃剑比喻：
"“It’s a double-edged sword because wildfires are getting more severe and larger under climate change and we need this work even more, but then the work gets more challenging,” said Susan Prichard..."
 【解析】double-edged sword 形象地描述了现状。because 引导原因状语从句，里面包含两个并列分句。but then 引导转折，指出了虽然需求迫切但实施难度增加的矛盾。 
【翻译】“这是一把双刃剑，因为在气候变化下野火变得更加严重且规模更大，我们比以往任何时候都更需要这项工作，但工作也因此变得更具挑战性，”苏珊·普里查德说道。 