passage 21 海洋生態(tài)系統(tǒng)不像陸地生態(tài)系統(tǒng)那樣好操作
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文章講解:
①Our terrestrial food supply comes from ecosystems transformed to produce a few comestible species through the removal of competitors, predators, and pests,?but?marine capture fisheries depend on the overall productivity of natural ecosystems. ②There is,?however, increasing concern about the impact of fishing and other human activities on marine ecosystems, which are now far from pristine. ③One option for moving toward both biodiversity and terrestrial food supply goals is to produce greater yields from less land, thereby freeing land for conservation purposes. ④By contrast, the objective of maintaining or?restoring the biodiversity of marine ecosystems may conflict with the objective of maintaining or increasing our food supply from the sea, since?the level of fishing required to achieve the latter may compromise the former.
①現(xiàn)象,客觀對比?T vs M ??② 提出問題 M
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?↓
? ? ? ? ? ? ? ? ? ? ? ③ 給出辦法 T? ???④ 提出對比 M?
1. The primary purpose of the passage is to 主旨
B
A. Examine the impact of certain research findings regarding changes to?ecosystem biodiversity.?IR,同時沒有體現(xiàn)文中對比
B. Discuss a possible implication of a difference between terrestrial and marine food supply sources.? 重在對比
C. Describe the consequences of a certain kind of interaction?between?terrestrial and marine ecosystems.? NE
D. Identify an area of ecosystem research in which there are significant?uncertainties.?NE
E. Present evidence that?undermines?one side of a?debate?about?biodiversity?and supports the other. 三個NE
D干擾,主看論證框架
?
2. According to the passage, increasing the food yield per unit of land can have which of the following effects? 直接細節(jié),對應③
E
A. Enabling more land to be used for?development?purposes NE
B.?Compromising?progress toward conservation goals?
C. Helping protect comestible species from?competition and predation?NE/IR
D. Helping reduce pressure on marine ecosystems?IR
E. Helping restore the biodiversity of terrestriale cosystems?
A干擾,選項要看完。單選選最優(yōu)。