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?
- 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. - 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. - Among dolphin calves born in the area along Florida’s Gulf
Coast, the mortality rate is highest among those with living siblings. - As dolphins age, they accumulate toxins from the environment more slowly than when they were young.
- 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 total market value of real estate in Altonville has steadily declined over the past four years. This decline has meant that the overall figure on which the city’s property tax is based—the assessed value of that real estate—has also declined. The percentage of assessed value that was paid as property taxes to the city, however, did not change from year to year during this period.
The information above most strongly supports which of the following?
- The percentage of Altonville’s yearly revenue that comes from money collected in property taxes did not change over the past four years.
- The percentage of Altonville’s yearly revenue that comes from money collected in property taxes has declined steadily over the past four years.
- The amount of revenue that Altonville collected from property taxes was lower last year than it was four years ago.
- During the past four years, Altonville officials increased tax rates on other sources of revenue such as retail sales and business profits.
- 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 |