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.

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

这道题我选C，不知对否？

The information above most strongly supports which of the following?

1. The percentage of Altonville’s yearly revenue that comes from money collected in property taxes did not change over the past four years.

2. The percentage of Altonville’s yearly revenue that comes from money collected in property taxes has declined steadily over the past four years.

3. The amount of revenue that Altonville collected from property taxes was lower last year than it was four years ago.

4. During the past four years, Altonville officials increased tax rates on other sources of revenue such as retail sales and business profits.

5. Altonville will soon require property owners to pay a higher percentage of the assessed value of their property as property tax.

这道题没有答案，不知大家认为应该选什么。谢谢了

First one I think the answer should be A that points about calves will live longer without mother's milk.

Second one I will pick C

第一个我选Ａ，文章先说了两个现象：１，female dophins将８０％的有毒物质都吸收到了喂baby的milk去了，２dophin calves的死亡率很高．因此将２个原因归结为１，加强就是说确实是female milk造成的．．

Ａ答案说了dophin calves在被断奶前其mother就被killed掉的成活率很高，意思就是没有了这些有毒物质的奶它们就可以大量的活下来．

Ｃ选项我认为是无关比较，和其兄弟姐妹比死亡率．．．怎么比法子？？

第二个偶不会～看到这个就郁闷．．．

Second question is a conclusion type of question.

we know that market value and property tax has decreased for four years.So what we will get to know.The revenue of the property tax in the last year would be the lowest in the past few year.So C would be the answer for sure.

oh!i've got it!!

thank u!!

第一个应该选A，第二个应该是C.

我对第二题的理解是：要抓住两个条件：（1）the assessed value of that real estate逐年下降了；（2）The
                    percentage of assessed value that was paid as property taxes to the city未变；

现在假设今年的assessed value 是1000，交5%的税，那么税款就是50；明年的assessed value下降为800，仍交5%的税，那么税金就变成40.可以看出税金是下降的，即政府收入是下降的。

上面的理解不知对否，请指教。