The Earth’s rivers constantly carry dissolved salts into its oceans. Clearly, therefore, by taking the resulting increase in salt levels in the oceans over the past hundred years and then determining how many centuries of such increases it would have taken the oceans to reach current salt levels from a hypothetical initial salt-free state, the maximum age of the Earth’s oceans can be accurately estimated.
Which of the following is an assumption on which the argument depends?
A. The quantities of dissolved salts deposited by rivers in the Earth’s oceans have not 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.
E. None of the salts carried into the Earth’s oceans by rivers are used up by biological activity in the oceans.
Answer: A
刚才看了个讨论贴大家都在讨论A和E....但是做为一个选了B的人....
我觉得...Which of the following is an assumption on which the argument depends?
上面的讨论是在下面那个假设的基础上成立的？
我觉得很明显是在所有河水含盐量不变的情况下成立的撒。。。。所以B
Which of the following is an assumption on which the argument depends?
究竟是啥意思？？？啥意思？？
