就要考试了，有几道逻辑JJ想请教大家！

就是海龟这道题，答案是什么？为什么呢？

A major chemical spill occurred five years ago at Baker’s Beach, the world’s sole nesting ground for Merrick sea turtles, and prevented nearly all the eggs laid that year from hatching.  Yet the number of adult female Merricks returning to lay their eggs at Baker’s Beach has actually increased somewhat since five years ago.  Clearly, environmentalists’ prediction that the world’s Merrick population would decline as a result of the spill has proven unfounded.

Which of the following, if true, most seriously undermines the argument offered in refutation of the environmentalists’ prediction?

A.      The chemical spill five years ago occurred at a time when there were neither Merrick sea turtles nor Merrick sea turtle eggs on Baker’s Beach.

B.      Female Merrick sea turtles begin returning to Baker’s Beach to lay their eggs when they are ten years old.

C.      Under normal conditions, only a small proportion of hatchling female Merrick sea turtles survive in the ocean until adulthood and return to lay their eggs at Baker’s Beach.

D.     Environmental pressures unrelated to the chemical spill have caused a significant decline in the population of one of the several species of sea birds that prey on Merrick sea turtle eggs.

E.      After the chemical spill, an environmental group rejected a proposal to increase the Merrick sea turtle population by transferring eggs from Baker’s Beach to nearby beaches that had not been affected by the spill.

这道题为什么选B呢？可否帮忙翻译一下各选项意思？

Because mining and refining nickels is costly, researchers have developed an alternative method for extracting nickels using Streptanthus polygaloides, a plant that absorbs and stores nickel from the soil as it grows. The researchers incinerated a crop of Streptanthus they grow in nickel-rich soil. By chemically extracting nickel form the ash, they produced 100 pounds of nickel per acre of land at a total cost per pound slightly above that of current mining.

Which of the following, if true, most strongly supports the conclusion that the use of Streptanthus to extract nickel will be commercially adopted? ( B)

A.      The season in which the researchers grew Streptanthus was an unusually favorable one, with the right amount of precipitation to maximize the growth rate of Streptanthus.

B.      Because lowering the concentration of nickel in the soil can make land much better for agriculture in general, a plot in which Streptanthus has been grown and harvested can be sold for substantially more than it cost

C.       More air pollution is generated for each pound of nickel produced by extracting it from Streptanthus than is generated using conventional mining and refining

D.      The land on which the researchers planted Streptanthus was unusually free of the various weeds that can compete with Streptanthus for water, nutrients, and sunlight.

E.       It is extremely rare for soil to contain higher concentrations of nickel than the concentrations present in the researchers’ experimental plot.

金融方面的知识比较薄弱，想了解一下为什么“导致债券(bond) 价格上升，其收益率会下降”？

83、股票与债券的收益与风险是成正比的，但是它们之间收益的差距正在加大。因为：由于投资顾问的收入是和损失的大小相关的，因此他们倾向于收益小但风险小的债券品种，由于大家都这么做，导致债券(bond) 价格上升，其收益率则下降。
            

债券收益率=每一债券每年派出的利息金额/债券的现价*100% 所以价格上升，即分母变大，分子不变，收益率下降。

五年前海滩污染影响海龟蛋孵化，但五年来回海滩产蛋的母海龟数量增加，故科学家预测海龟减少无根据。问削弱，选B。母海龟要长到十岁才回沙滩产蛋，就是说5年前回来产蛋的是15年前出生10岁回来产蛋的母海龟，4年前回来的是14年前出生的10岁的母海龟……那个时候沙滩还没有污染

镍那道问的是哪个选项能使这一新的提炼过程更具有经济可行性。已知挖费钱，化学方法经济上更能被接受，B又说土壤种的镍被提取后，土地还能卖更多钱，所以更经济。

Thank you so much ))))))))