28. What does the new study imply regarding oaks and sweetgums?
- A. They affect the growth of other trees.
- B. They absorb less carbon than expected.
- C. They harm people’s health indirectly.
- D. They raise the local temperature slowly.
答案：C
答案句：Harmless by itself, isoprene interacts rapidly with polluting nitrogen oxides released by vehicles, buildings and industry to form ground-level ozone (臭氧) — a major factor in many breathing problems.
参考译文：异戊二烯本身无害，但它会迅速与车辆、建筑和工业排放的污染性氮氧化物反应，形成地面臭氧——这是许多呼吸系统问题的一个主要因素。
定位线索：题干“new study imply regarding oaks and sweetgums”→答案句取自第2段“isoprene interacts rapidly...to form ground-level ozone”；文中“a major factor in many breathing problems”对应选项C“harm people's health indirectly”。
解析：题干问新研究对橡树和枫香树的暗示。答案句说明它们产生的异戊二烯与氮氧化物反应生成臭氧，而臭氧是呼吸问题的因素，因此它们间接危害健康，选C。A项“影响其他树木生长”、B项“吸收碳少于预期”、D项“提高温度”均无原文依据，属于无中生有。
29. Which of the following may Commane suggest based on their study?
- A. Cutting down the isoprene-producing trees.
- B. Suspending tree-planting for a few decades.
- C. Changing the species of trees in new plantings.
- D. Removing isoprene released by existing trees.
答案：C
答案句：“We’re all for planting more trees. They bring so many good things,” said study coauthor Róisín Commane. “But if we’re not careful, we could make air quality worse.” … The research, carried out by scientists at the Columbia Climate School and other institutions, found that if the city maintains past species patterns in new plantings, isoprene production in Manhattan in coming decades will go up by about 140%, and resulting summer ozone levels as much as 30%.
参考译文：“我们完全支持种植更多树木。它们带来了很多好处，”研究合著者Róisín Commane说。“但如果我们不小心，我们可能会让空气质量变得更糟。” … 由哥伦比亚气候学院和其他机构的科学家进行的研究发现，如果该市在新种植中保持过去的物种模式，未来几十年曼哈顿的异戊二烯产量将增加约140%，由此产生的夏季臭氧水平将增加多达30%。
定位线索：题干“Commane suggest based on their study”→答案句取自第4段Commane的引语“But if we’re not careful, we could make air quality worse”及第3段研究结论“if the city maintains past species patterns in new plantings...”；文中“maintains past species patterns”对应选项C“Changing the species of trees in new plantings”（改变新种植的树种）。
解析：题干问Commane基于研究可能建议什么。答案句中Commane说“如果我们不小心，空气质量可能变差”，而研究结论指出“如果保持过去的物种模式，异戊二烯产量和臭氧水平将上升”，由此可推断应改变新种植的树种，即选项C。选项A“砍伐产生异戊二烯的树”和B“暂停植树几十年”均与Commane“我们完全支持种更多树”的态度矛盾，属无中生有；选项D“移除现有树木释放的异戊二烯”文中未提及，且与“不把树当敌人”的观点不符，属偷换概念。
30. What does the underlined phrase “oblivious to” in paragraph 5 mean?
- A. Honest about.
- B. Unaware of.
- C. Related to.
- D. Optimistic about.
答案：B
答案句：The Parks Department is not oblivious to the issue. A study carried out by some of its researchers several years ago concluded that city trees did release isoprene.
参考译文：公园管理部门并非对这个问题 oblivious。几年前其一些研究人员进行的一项研究得出结论，城市树木确实释放异戊二烯。
定位线索：题干“oblivious to”→答案句取自第5段首句；文中“not oblivious to”与后文“A study...concluded”对应，说明他们知道该问题，对应选项B“Unaware of”。
解析：题干问划线词含义。答案句后文说公园部门的研究已得出结论，说明他们知道异戊二烯问题，因此“not oblivious to”意为“并非不知道”，选B。A项“诚实”、C项“相关”、D项“乐观”均不符合语境，属于偷换概念。
31. What would Auyeung probably advocate?
- A. Reducing car use in daily life.
- B. Providing animals with new habitats.
- C. Controlling population growth.
- D. Doing more research on the problem.
答案：A
答案句：“We could plant any trees we want to, if we just rethink our car-centric lifestyle,” she said.
参考译文：她说：“如果我们重新思考以汽车为中心的生活方式，我们就可以种植任何我们想要的树。”
定位线索：题干“Auyeung probably advocate”→答案句取自第5段末句；文中“rethink our car-centric lifestyle”对应选项A“Reducing car use in daily life”。
解析：题干问Auyeung可能倡导什么。答案句明确说“重新思考以汽车为中心的生活方式”，即减少汽车使用，选A。B项“为动物提供新栖息地”、C项“控制人口增长”、D项“做更多研究”均无原文直接支持，属于无中生有。