26. By saying “one of the harder challenges,” the author implies that.
- A. global climate change may get out of control
- B. people may misunderstand global warming
- C. extreme weather conditions may arise
- D. forests may become a potential threat
答案：D
答案句：Forests give us shade, quiet and one of the harder challenges in the fight against climate change. Even as we humans count on forests to soak up a good share of the carbon dioxide we produce, we are threatening their ability to do so. The climate change we are hastening could one day leave us with forests that emit more carbon than they absorb.
参考译文：森林给我们提供荫凉、宁静，以及对抗气候变化中一个更艰巨的挑战。即使我们人类指望森林吸收我们产生的大量二氧化碳，我们却在威胁它们这样做的能力。我们正在加速的气候变化有一天可能会让我们拥有排放碳多于吸收碳的森林。
定位线索：题干“one of the harder challenges”→答案句首句“one of the harder challenges in the fight against climate change”；文中“forests that emit more carbon than they absorb”对应选项D“forests may become a potential threat”（森林可能成为潜在威胁）。
解析：题干问作者说“one of the harder challenges”暗示什么。答案句指出森林既是气候变化的挑战，且人类威胁其吸碳能力，气候变化可能导致森林排放碳多于吸收碳，即森林从碳汇变为碳源，成为潜在威胁，对应D。A“气候变化失控”、B“误解全球变暖”、C“极端天气”均无原文依据，属于无中生有。
27. To maintain forests as valuable “carbon sinks,” we may need to.
- A. preserve the diversity of species in them
- B. accelerate the growth of young trees
- C. strike a balance among different plants
- D. lower their present carbon-absorbing capacity
答案：D
答案句：Helping forests flourish as valuable “carbon sinks” long into the future may require reducing their capacity to absorb carbon now.
参考译文：帮助森林在未来长期作为宝贵的“碳汇”繁荣发展，可能需要降低它们现在吸收碳的能力。
定位线索：题干“maintain forests as valuable carbon sinks”→答案句“Helping forests flourish as valuable 'carbon sinks' long into the future”；文中“reducing their capacity to absorb carbon now”对应选项D“lower their present carbon-absorbing capacity”（降低它们目前吸收碳的能力）。
解析：题干问维持森林作为碳汇可能需要什么。答案句直接说明需要“reducing their capacity to absorb carbon now”，即降低当前吸碳能力，与D完全对应。A“保护物种多样性”、B“加速幼树生长”、C“平衡不同植物”均无原文依据，属于无中生有。
28. California’s Forest Carbon Plan endeavors to.
- A. cultivate more drought-resistant trees
- B. reduce the density of some of its forests
- C. find more effective ways to kill insects
- D. restore its forests quickly after wildfires
答案：B
答案句：The state’s proposed Forest Carbon Plan aims to double efforts to thin out young trees and clear brush in parts of the forest.
参考译文：该州提出的森林碳计划旨在加倍努力，疏伐部分森林中的幼树并清除灌木。
定位线索：题干“California's Forest Carbon Plan endeavors to”→答案句“The state's proposed Forest Carbon Plan aims to”；文中“thin out young trees and clear brush”对应选项B“reduce the density of some of its forests”（降低部分森林的密度）。
解析：题干问加州森林碳计划努力做什么。答案句指出计划旨在“thin out young trees and clear brush”，即疏伐幼树和清除灌木，这会降低森林密度，对应B。A“培育抗旱树”、C“更有效杀虫”、D“火灾后恢复”均无原文依据，属于无中生有。
29. What is essential to California’s plan according to Paragraph 5?
- A. To handle the areas in serious danger first.
- B. To carry it out before the year of 2020.
- C. To perfect the emissions-permit auctions.
- D. To obtain enough financial support.
答案：A
答案句：That’s only a small share of the total acreage that could benefit, about half a million acres in all, so it will be vital to prioritize areas at greatest risk of fire or drought.
参考译文：这只是可能受益的总面积（总共约50万英亩）的一小部分，因此优先处理火灾或干旱风险最大的地区至关重要。
定位线索：题干“Paragraph 5”→答案句取自第5段“so it will be vital to prioritize areas at greatest risk of fire or drought”；文中“prioritize areas at greatest risk”对应选项A“To handle the areas in serious danger first”（优先处理危险严重的地区）。
解析：题干问根据第5段，加州计划的关键是什么。答案句明确指出“vital to prioritize areas at greatest risk of fire or drought”，即优先处理风险最大的地区，对应A。B“2020年前实施”、C“完善拍卖”、D“获得足够资金”均非第5段强调的关键点，属于答非所问。
30. The author’s attitude to California’s plan can best be described as.
- A. ambiguous
- B. tolerant
- C. supportive
- D. cautious
答案：C
答案句：California’s plan, which is expected to be finalized by the governor next year, should serve as a model.
参考译文：加州的计划预计明年由州长最终确定，应该成为典范。
定位线索：题干“author's attitude to California's plan”→答案句“should serve as a model”；文中“should serve as a model”（应成为典范）体现作者正面评价，对应选项C“supportive”（支持的）。
解析：题干问作者对加州计划的态度。答案句使用“should serve as a model”，表明作者认为该计划值得效仿，是积极肯定的态度，对应C。A“模糊的”、B“容忍的”、D“谨慎的”均与原文的积极评价不符，属于程度或性质错误。