Carotenoids, a family of natural pigments, form an important part of the colorful signals used by many animals. Animals acquire carotenoids either directly (from the plants and algae that produce them) or indirectly (by eating insects) and store them in a variety of tissues. Studies of several animal species have shown that when choosing mates, females prefer males with brighter carotenoid- based coloration. Owens and Olson hypothesize that the presence of carotenoids, as signaled by coloration, would be meaningful in the context of mate selection if carotenoids were either rare or required for health. The conventional view is that carotenoids are meaningful because they are rare: healthier males can forage for more of the pigments than can their inferior counterparts. Although this may be true, there is growing evidence that carotenoids are meaningful also because they are required: they are used by the immune system and for detoxification processes that are important for maintaining health. It may be that males can use scarce carotenoids either for immune defense and detoxification or for attracting females. Males that are more susceptible to disease and parasites will have to use their carotenoids to boost their immune systems, whereas males that are genetically resistant will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead.
【OG19-P384-445题】The passage suggests that relatively bright carotenoid-based coloration is a signal of which of the following characteristics in males of certain animal species?
根据题干可以定位到Studies of several animal species have shown that when choosing mates, females prefer males carotenoids with brighter carotenoid-based coloration.所以动物的颜色越鲜艳，就越容易被选作为配偶，E选项正确。
A选项，mating behavior 是交配行为，文章讨论的是作为配偶，而不是交配行为，排除。
我觉得D应该是不全面，defense(缺少）+ detoxification(recovery)=immune system 完善=fitness 所以E比较好
B fight后面缺少宾语，如果说是disease，那可能是对的； C 没有提及feeding preference D recovery不对，应是defend E正确
D ：Recovery恢复和文中的免疫系统不一样 免疫是还没有受到感染
2018-10-30 21:37:47 回复
According to the passage, Kerber argued that political leaders thought that the form of government adopted by the United States after the American Revolution depended on which of the following for its success?
【OG19-P387-452题】According to the passage, Kerber argued that political leaders thought that the form of government adopted by the United States after the American Revolution depended on which of the following for its success?