求解~~GWD-TN-9 Q-29

gamedream

The earth's rivers constantly carry dissolved salts into its ocean. Clearly, therefore, by taking the resulting increase in salt levels in the ocean over the past hundred years and then determining how many centuries of such increase it would have taken the oceans to reach the oceans to reach current salt levles from a hypothetical initial salt-free state, the maximum age of the Earth's oceans can be accurately estimated.

A. The quantities of dissolved salts deposited by rivers in the Earth's oceans have ont been unusually large during the past hundred years.

B. At any given time, all the Earth's rivers have about the same salt levels.

C. There are salts that leach into the Earth's oceans directly from the ocean floor.

D. There is no method superior to that based on salt levels for estimating the maximum age of the Earth's oceans.

D. None of the salts carried into the Earth's oceans by rivers are used up by biological activity in the ocean.
答案选择的是A  我选的E  费解啊 ~~~~~~~~~

gamedream

自己顶一个 ~~  求解

juliangogo

哈哈我也选E 觉得A很没道理呢~~