36. According to Paragraph 1, Swetnam was surprised by
- A. the scarcity of tree-ring research in the U.S.
- B. the firefighting measures in ancient Europe.
- C. the forest management practices in the 1970s.
- D. the number of wildfires in precolonial times.
答案：D
答案句：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.
参考译文：但当斯韦特南在亚利桑那大学树木年轮研究实验室读研究生时，他惊讶地发现了一份可追溯到欧洲殖民者到达这片大陆之前数百年的反复火灾记录。他分析的一些树木的年轮中有20多处火灾疤痕。
定位线索：题干“According to Paragraph 1”→答案句取自第1段“he was surprised to find a record of repeated blazes dating back hundreds of years before European colonists arrived”；文中“repeated blazes”对应选项D“the number of wildfires in precolonial times”。
解析：题干问斯韦特南惊讶于什么，答案句直接说他惊讶地发现欧洲殖民者到来前数百年就有反复火灾的记录，即前殖民时代火灾数量多，对应D。A项“树轮研究稀缺”、B项“古代欧洲消防措施”、C项“20世纪70年代森林管理”均无中生有。
37. Paragraph 2 mainly focuses on
- A. the causes of previous burns.
- B. the treatment of diseased trees.
- C. the benefits of low-severity fires.
- D. the importance of forest ecosystems.
答案：C
答案句：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.
参考译文：相反，越来越多的研究表明，频繁、低强度的火灾使许多生态系统更健康。它们清除了森林中枯死和患病的树木，减少了竞争并遏制了疾病的传播。由于可燃物无法在地表堆积，火灾往往移动缓慢，并在到达先前燃烧的痕迹时逐渐熄灭。
定位线索：题干“Paragraph 2 mainly focuses on”→答案句取自第2段“frequent, low-severity fires made many ecosystems healthier”；文中“made many ecosystems healthier”对应选项C“the benefits of low-severity fires”。
解析：第2段首句提出低强度火灾使生态系统更健康，随后具体说明其好处（清除死树、减少竞争、遏制疾病、减缓火势），整段围绕低强度火灾的益处展开，对应C。A项“先前燃烧的原因”、B项“病树处理”、D项“森林生态系统重要性”均非段落主旨，属于以偏概全或偏离主题。
38. What did the study find about the wildfires over the past few decades?
- A. Their intensity has vastly fluctuated.
- B. Their frequency has markedly decreased.
- C. Their threats have been underestimated.
- D. Their records have been misinterpreted.
答案：B
答案句：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.
参考译文：在这项研究中，研究人员将历史上的火灾节奏与过去几十年记录的野火进行了比较，并发现了一个惊人的不足。NAFSN站点经历的火灾数量不到没有火灾抑制情况下预期数量的四分之一。
定位线索：题干“What did the study find about the wildfires over the past few decades”→答案句取自第3段“compared the historical fire cadence with the wildfires recorded over the past few decades”；文中“less than a quarter of the number of fires”对应选项B“Their frequency has markedly decreased”。
解析：题干问研究发现过去几十年野火的情况，答案句指出实际火灾数量不到预期四分之一，即频率显著下降，对应B。A项“强度大幅波动”、C项“威胁被低估”、D项“记录被误解”均未提及，属于无中生有。
39. What can be inferred about modern firefighting?
- A. Its workforce needs more training.
- B. Its effectiveness is questioned by the public.
- C. It may render traditional tactics useless.
- D. It may make severe fires harder to put out.
答案：D
答案句：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.”
参考译文：国际野火协会前主席凯利·马丁表示，这一不足证明了现代消防的有效性。“然而，抑制和气候变化的综合后果已经削弱了人类抑制火灾的能力，尤其是在最危险的天气条件下点燃的火灾。”
定位线索：题干“What can be inferred about modern firefighting”→答案句取自第4段“suppression and climate change have eroded humanity's ability to suppress fires”；文中“eroded humanity's ability to suppress fires”对应选项D“It may make severe fires harder to put out”。
解析：题干问关于现代消防可推断出什么，答案句说抑制和气候变化削弱了人类抑制火灾的能力，尤其是在最危险天气下，可推断现代消防可能使严重火灾更难扑灭，对应D。A项“劳动力需要更多培训”、B项“公众质疑其有效性”、C项“使传统策略无用”均无依据，属于无中生有。
40. Both Martin and Prichard would agree that
- A. it is challenging to predict large wildfires.
- B. it is urgent to assess the use of planned fires.
- C. it is necessary to introduce prescribed burns.
- D. it is rewarding to double fire detection efforts.
答案：C
答案句：To prevent entire ecosystems from going up in smoke, Martin said, people must bring healthy fire back to places that need it. At Yosemite National Park, Martin oversaw the use of what is known as prescribed burns to make the landscape more resilient. … “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.
参考译文：马丁说，为了防止整个生态系统化为灰烬，人们必须将健康的火灾带回需要它的地方。在约塞米蒂国家公园，马丁监督了所谓的计划烧除的使用，以使景观更具韧性。……华盛顿大学火灾生态学家苏珊·普里查德说：“这是一把双刃剑，因为气候变化下野火越来越严重、规模越来越大，我们更需要这项工作，但工作却变得更加困难。”
定位线索：题干“Both Martin and Prichard would agree”→答案句取自第5段“people must bring healthy fire back”和第6段“we need this work even more”；文中“prescribed burns”和“this work”对应选项C“it is necessary to introduce prescribed burns”。
解析：马丁说必须把健康的火灾带回需要的地方，并监督计划烧除；普里查德说气候变化下更需要这项工作，两人都认为引入计划烧除是必要的，对应C。A项“预测大火困难”、B项“评估计划烧除紧迫”、D项“加倍火灾探测努力”均未提及，属于无中生有。