Global warming looks like it will be a bigger problem for the world’s fish species than scientists first thought; A new study sh

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问题     Global warming looks like it will be a bigger problem for the world’s fish species than scientists first thought; A new study shows that when fish are laying eggs, they are more vulnerable to hotter water. With medium-level human-caused climate change expected by the end of the century, the world’s oceans, rivers and lakes will be too hot for about 40% of the world’s fish species in the egglaying stage, according to a study. That means they could go extinct or be forced to change how and where they live and reproduce.
    Until now, biologists had just studied adult fish. For adult fish, around 2% to 3% of the species would be in the too-hot zone in the year 2100 with similar projected warming. So using this new approach reveals a previously unknown problem for the future of fish, scientists said. In a worst case climate change scenario the figure for species in trouble jumps to 60%. These vulnerable times in the life of a fish make this a "bottleneck" in the future health of species, said Hans-Otto Portner, a marine biologist at the Alfred Wegener Institute in Germany.
    A marine heatwave last year caused large numbers of migrating salmon fish to die throughout Alaska’s rivers. It also killed off cod fish eggs, showing what a warmer future might be like, said Flemming Dahlke, a marine biologist at the institute. "With those fishes most sensitive to warming waters, it means fish populations won’t be able to replace themselves," said Rutgers University ecologist Malin Pinsky. "Without reproduction and offspring, we have no fish, no fishing and no fish on our plates. "
    In studying 694 species, Dahlke and Portner found some of the fish likely to be hardest hit by this phenomenon include Alaska pollock—the biggest fishery in the United States and the source of fast food fish slices—and well-known fish species such as sockeye salmon, brown trout, bonito, barracuda and swordfish. "The more we allow temperature to change, the more we will lose the natural foundation of human life, including food from the sea," Portner said. When it gets too warm for living, the species could still possibly move to someplace cooler or lay at another time, but that’s not easy, Dahlke said. "This could mean a lot of problems to many species.
Hotter water would be unacceptable for fish species because________.

选项 A、they would go extinct in hot water
B、they are more sensitive in egg-laying stage
C、they have to adjust the habitation place
D、they cannot breed in hot water

答案B

解析 根据题干关键词hotter water可定位至第一段第一句A new study shows that when fish are laying eggs,they are more vulnerable to hotter water,由此可知,B项是原文的同义替换,故为正确答案。根据第一段的最后一句,That means they could go extinct or be forced to change how and where they live and reproduce,可以得知鱼类可能会灭绝,但并不是一定会灭绝,故A项错误。C项是“温度更高的水不适合鱼类生活”的后果,而不是原因,逻辑错误,因此排除。D项曲解文意,文中只提到产卵更容易受到较高水温的影响,并未说不能在热水中繁殖,故排除。
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