問題詳情

Passage IIPassage U.A study of 100 reefs, published in Science Magazine, shows the interval between bleaching events in recent decades has shortened dramatically. It has gone from once every 25-30 years in the early 1980s to an average of just once every six years today. Bleaching is caused by anomalously warm water, which prompts coral polyps to eject their symbiotic algae. This drains the corals of their color and is fatal unless conditions are reversed in a reasonably short time. But even if temperatures fall back quickly, it can still take many years for damaged reefs to fully recover. Aside from their beauty, tropical corals provide important ecosystem services upon which the livelihoods of many millions of people depend. Reefs, for example, afford coastal protection from big waves, storms, and floods; they also act as key spawning and nursery grounds for economically important fish and other aquatic species. This study concentrates on the climate challenge to corals, but many reefs are also experiencing other stresses, including pollution, overfishing and habitat destruction.
45.Which of the following statements is TRUE?
(A).The bleaching events of the coral reefs were more frequent in the 1980s than today.
(B).The interval between bleaching events of the coral reefs has come to a halt today.
(C).The interval between bleaching events of the coral reefs today has diminished almost by one-fourth to one-fifth in recent decades.
(D).The interval between bleaching events of coral reefs has been widening ever since the early 1980s.

參考答案

答案：[無官方正解]
難度：非常困難0
統計：A(0),B(0),C(0),D(1),E(0)

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