[求助] GWD-1-14

答案是A, 可是藕觉得不对。

题干中这句话怎么理解？？

Coal output per miner in Tribnia is double what it was five years ago

藕觉得她只是说现在的生产率是5年前的两倍，过去5年间的生产率是多少无从而知，所以答案A.....不知道怎么得出来的？

Q14:
That the application of new technology can increase the productivity of existing coal mines is demonstrated by the case of Tribnia's coal industry.  Coal output per miner in Tribnia is double what it was five years ago, even though no new mines have opened.

Which of the following can be properly concluded from the statement about coal output per miner in the passage?

A. If the number of miners working in Tribnian coal mines has remained constant in the past five years, Tribnia's total coal production has doubled in that period of time.
B. Any individual Tribnian coal mine that achieved an increase in overall output in the past five years has also experienced an increase in output per miner.
C. If any new coal mines had opened in Tribnia in the past five years, then the increase in output per miner would have been even greater than it actually was.
D. If any individual Tribnian coal mine has not increased its output per miner in the past five years, then that mine's overall output has declined or remained constant.
E. In Tribnia the cost of producing a given quantity of coal has declined over the past five years.

每名矿工的生产率在5年时间内翻了一倍，所以A说如果矿工数量不变，那么总产量肯定是翻了一倍了。

总产量＝矿工数量x每名矿工的生产率

对，应该是这样解释。但想想这个翻倍的过程，从一倍到两倍，时间跨度是5年。可能前4年都是一倍，只最后一年发生了变化到2倍。如果是这样，即使矿工人数不遍，5年的产量也不会翻倍。

G-craker, 题目比较的只是第6年和第1年的数据，和5年中任何一年产量或累计产量等都无关吧。

对呀，是无关。这就是为什么A藕觉得不对，A讲的是5年中的产量会翻倍，藕推不出来，is there anybody elso, who can prove A is correct?

A. If the number of miners working in Tribnian coal mines has remained constant in the past five years, Tribnia's total coal production has doubled in that period of time.

你只管头管尾就行了。

原文：Coal output per miner in Tribnia is double what it was five years ago：现在每个矿工煤产量是5年前的两倍。就是说5年前是1倍，现在就是2倍。

A：Tribnia's total coal production has doubled in that period of time意思为：在这5年中，产量翻了两倍。就是说现在产量是5年前的2倍。

藕晓得的，只管头尾。Thank u, lawyer.

总产量＝矿工数量x每名矿工的生产率*(working time/矿工)

矿工数量x每名矿工的生产率=mine的生产率

So, I think A is not really logical.  Right?