阅读鸡精Passage 219求大神解答～～

啊GRE好难

Passage 219Ecologists had assumed that trees in the consistently warm tropics grew at a slow but steady rate, unvarying from year to year. However, a study at La Selva, Costa Rica, showed that trees grew less in hotter years and more in cooler ones: between 1984 and 2000, dramatic differences occurred in the six species of trees studies, with trees adding twice as much wood in some cooler years as they did in the scorching（酷热的） El Nino year of 1997-1998. Because tree growth is an index of the balance between photosynthesis, in which trees absorb carbon dioxide (CO2) from the atmosphere and release oxygen, and respiration, in which the opposite occurs, the La Selva data were the first hint that rapidly rising global temperatures, driven by human-generated emissions of CO2, may be pushing tropical forests to release more CO2, thereby intensifying global warming. This raised serious questions about a popular theory that tropical forests act as a sponge, soaking up much of the excess CO2 that humans pump into the atmosphere. The La Selva data are consistent with a model of global CO2 flux developed by Keeling, who concluded that the amount of CO2 taken up in tropical landmasses rose in cooler years and fell in hotter ones, accounting for year-to-year changes in the amount of CO2 that stays in the atmosphere.

3. The passage suggests that as temperatures rise, trees in the tropical regions  （D)
A. continue to grow at a slow but steady rate
B. grow less and intensify photosynthesis
C. emit more CO2 and oxygen
D. increase overall respiration and decrease overall photosynthesis
E. grow more and absorb more CO2


这是我自己列的一个小框架：

	Hotter Years	Cooler Years	Reason and Evidence Stated
	Trees Grew less Less wood Infers less photosynthesis and more respiratory	Trees Grew more More wood Infers more photosynthesis (where CO2 is absorbed)	“However, a study..1997-1998”
Challenges the “sponge theory” that tropical forests soak up CO2	Release more CO2 and intensify global warming		“La Selva Data” Consistent with Keeling’s model of global CO2

-1 第三问中D选项的"increase overall respiration"是如何推断出来的呀？读完文章，我怎么觉得temperature rise这种情况只能推断出decrease in overall photosynthesis?  于是我就在A和D中纠结选了A...
-2 划线的那一部分我好像没有怎么看明白，求翻译

                                       
                                
                        
               

Coraxin

我是这么理解的，“the La Selva data were the first hint that rapidly rising global temperatures, driven by human-generated emissions of CO2, may be pushing tropical forests to release more CO2, thereby intensifying global warming. ” 是这道题判断c的关键

作者在文章中说树木生长可以视为光合作用 （吸收co2释放氧气）和夜间呼吸作用 （释放co2吸收氧气）之间平衡度指数 ，而la selva 数据即成为首个暗示我们全球气温上升会使热带森林释放更co2 （the La Selva data were the first hint that rapidly rising global temperatures, driven by human-generated emissions of CO2, may be pushing tropical forests to release more CO2， 暗示：平衡不再，呼吸作用（respiration）更多，光合作用减少，之后作者在文章最后提到，La Selva 数据与co2模型有一致性（The La Selva data are consistent with a model of global CO2 flux developed by Keeling ），进一步暗示可信度，至此，作者也并没有任何反对的观点，那么结合“first hint” 和 结尾co2模型结果， 随着全球气温上升 （as temperatures rise, trees in the tropical regions），热带地区的树：
A. 无法推断出是不是slow but steady， 因为文中只提到冷热年生长情况对比
D. 呼吸作用更多，光合作用减少
最后想问楼主是从哪里找到2019-2020的鸡精啊？可不可以分享？或者有偿也可以。。。找寂静实在头干。。。。

啊GRE好难

Coraxin 发表于 2020-7-14 09:19
我是这么理解的，“the La Selva data were the first hint that rapidly rising global temperatures, dri ...

我刷的是张巍最新版300的阅读jj～它们的公众号上就可以直接去下载，免费哒

我又想了下.. 我不选D的原因貌似是我自己主观臆断了less wood并没有办法代表了more respiration（因为我在想树木怎么做呼吸作用？？），但是题目中好像并无在说这个more respiration 是树木直接导致的。作者好像就只是在文章提到了有这个平衡 可能是我想多了，谢谢你的分析！！

Coraxin

好嘞 谢谢楼主～～