1.         GWD-27-Q35

In polluted environments, dolphins gradually accumulated toxins in their body fat, and the larger the dolphin the more accumulated toxin it can tolerate.  Nearly 80 percent of the toxins a female dolphin has accumulated pass into the fat-rich milk her nursing calf ingests.  Therefore, the unusually high mortality rate among dolphin calves in the industrially contaminated waters along Florida’s Gulf
                Coast is probably the result of their being poisoned by their mother’s milk.

Which of the following, if true, most strengthens the argument?

1. The survival rate of firstborn dolphin calves in the area along Florida’s Gulf
                       Coast is highest for those whose mothers were killed before they were weaned.

2. The rate at which adult dolphins living in the waters along Florida’s Gulf
                       Coast accumulate toxins is no higher than that of adult dolphins in comparably polluted waters elsewhere.

3. Among dolphin calves born in the area along Florida’s Gulf
                       Coast, the mortality rate is highest among those with living siblings.

4. As dolphins age, they accumulate toxins from the environment more slowly than when they were young.                                              

E. Dolphins, like other marine mammals, have a higher proportion of body fat than do most land mammals.       

答案是A,   可是我一点思路也没有,谁能帮我解释一下A选项,并给一个推理关系呀   先谢                         

有毒的母乳--导致area along Florida’s Gulf
            Coast
            幼仔的死亡率高

问加强。

A：在firstborn dolphin calves in the area along Florida’s Gulf
            Coast中，
            母亲在其断奶前就死亡的dolphin calves 存活率最高。

这些存活率高的dolphin calves 和别的dolphin calves 相比，区别在于母亲是否在其断奶前就死亡。也就是说，dolphin calves 的存活率高低和其喂养母乳时间长短，多少有关

我是这么理解的。。。望NN们来指正~

干的漂亮

请教各位大大们,这题A选项问一个非常弱智的问题

虽然A确实导出奶与致死率有关,

但我想请问一下A表示母dolphin在断奶前死掉它孩子存活率高??

若这母dolphin在断奶前死掉它孩子怎么生出来???????

(Ps.可能是非常可笑的问题连我都觉得自己快晕了………..请各位大大解救这个逻辑白痴???唉….)

心情理解，但是a表示孩子在断奶前妈妈死掉，注意their和they在一句话里必然指代同一对象

firstborn dolphin
        

是不是可以这样理解,第一胎的存活率比较高,后面因为感染了毒素, 接着生下的存活率就低了.  这样理解是不是就更加能加强点了.