GWD 18-35 逻辑

呼啸700

35. GWD27-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.（答案）
   
   
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.
   
   
5. Dolphins, like other marine mammals, have a higher proportion of body fat than do most land mammals.
   
   不知道为什么支持了 ＮＮ们解释一下
   
   

sdcar2010

weaned means stopping breast-feeding. If a dophin mother stops feeding her milk, which is contaminated with toxins to the her baby dolphin, the baby dophin would have no more toxin coming from the contaminated mother milk. Thus these baby dophins would have a higher survival chance than other who still feed on their moms.

A sheds more favorable light on the conclusion of the argument, whcih is the last sentence of the stimulus.

呼啸700

OK  I know