In line with longstanding initiatives to expand its green spaces, New York City is planting tens of thousands of trees each year. They provide shade, lower surface temperatures, absorb a surprising amount of airborne carbon, remove tiny pollutants, and provide wildlife habitat along with just plain beauty.

Something could go wrong, though, according to a new study. Oaks and sweetgums, which currently account for a majority of the city’s trees, produce huge amounts of a chemical substance called isoprene. 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.

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%.

“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 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. “We didn’t make a big deal of that,” said Novem Auyeung, a Parks Department senior scientist. She said trees should not be viewed as the enemy. “We could plant any trees we want to, if we just rethink our car-centric lifestyle,” she said.

“We’re not going to go cutting down any big old oaks,” and neither will the department completely stop planting new ones, said Auyeung. “You have to think about what you would lose if you do that.” Oaks are keystone species, she pointed out, providing food and habitat for native insects, birds and other animals.

1.1. 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.

解析：选C。推理判断题。第二段揭示了完整的因果链：栎树和枫香树产生大量异戊二烯（isoprene）→ 异戊二烯与氮氧化物反应形成地面臭氧（ozone）→ 臭氧是许多呼吸系统问题的主要因素。所以这两种树通过 "释放化学物质→生成臭氧→危害呼吸" 的链条间接损害人类健康，故 C 正确。干扰项辨析：A"影响其他树木生长" 文中无依据；B"吸碳比预期少" 与首段 "absorb a surprising amount of airborne carbon" 矛盾；D"升高温度" 张冠李戴 —— 树木的作用是降低地表温度，异戊二烯的隐患是臭氧而非升温。此题考查理清 "树木→异戊二烯→臭氧→健康" 的多层因果链。

2.2. 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.

解析：选C。推理判断题。研究结论的关键句是 "if the city maintains past species patterns in new plantings, isoprene production...will go up by about 140%"（如果该市在新种植中保持过去的树种模式，异戊二烯产量将上升约 140%）—— 隐含之意是：只要改变新种植的树种模式，就能避免臭氧问题恶化。结合科曼的话 "We're all for planting more trees"（完全赞成种树）"if we're not careful, we could make air quality worse"（不小心就会让空气变差），她的建议是 "继续种树但调整品种"，故 C 正确。干扰项辨析：A"砍树" 与科曼 "完全赞成种树" 的表态矛盾；B"暂停植树" 同样违背她支持种树的立场；D"清除异戊二烯" 技术上不可行且文中未提及。此题考查从研究假设（if...maintains past species patterns）反推建议。

3.3. What does the underlined phrase "oblivious to" in paragraph 5 mean?

A Honest about.

B Unaware of.

C Related to.

D Optimistic about.

解析：选B。词义猜测题。画线句 "The Parks Department is not oblivious to the issue"（公园部门并非 oblivious to 这个问题），后文紧接着解释 "A study carried out by some of its researchers several years ago concluded that city trees did release isoprene"（几年前其研究人员的研究已得出结论：城市树木确实释放异戊二烯）—— 说明公园部门知道这个问题，故 "not oblivious to" 意为 "并非不知道 / 并非没意识到"，oblivious to = unaware of（未意识到的），选 B。A honest about（诚实）、C related to（相关）、D optimistic about（乐观）代入均无法与 "其研究早已得出结论" 形成合理的 "否定 + 解释" 逻辑。此题考查利用后文补充说明反推短语含义。

4.4. 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.

解析：选A。推理判断题。奥永说 "We could plant any trees we want to, if we just rethink our car-centric lifestyle"（如果我们只是重新思考以汽车为中心的生活方式，就可以种任何想种的树）。异戊二烯必须与 "车辆、建筑和工业排放的氮氧化物" 反应才生成臭氧，而氮氧化物主要来自汽车。因此她主张的核心是改变依赖汽车的生活方式、减少用车，故 A 正确。干扰项辨析：B"新栖息地" 是栎树本身的功能（为动物提供栖息地），不是她的主张；C"控制人口" 无中生有；D"更多研究" 与她的立场不符 —— 公园部门早已做过研究，她强调的是生活方式改变而非继续研究。此题考查抓住 "rethink our car-centric lifestyle" 这一关键表态。