gwd-1-14不懂：（

sureno1

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?

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.

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.

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.

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.

In Tribnia the cost of producing a given quantity of coal has declined over the past five years.

选A，

为什么不选C呢？？

sureno1

A的意思是：

如果矿工人数五年内没有变化的话，在那段时间里总产量加倍。

么？？？

hl2006

A:Output/miner=(Total output)/(Total Miner), take a look at the orignal passage,what they said exactly match the conclusion A drawed

C:first,it is a hypothesis, second, C said if there is new coat mine opened, but C does not mention about the total number of miner, therefore, choice C does not match the fact that output/miner doubled...

Jocelynsu

A的时间不明确。。。in that period of time如果是指5年以来的话，总产量肯定不止翻两倍啊。

Jocelynsu

ETS的人数学一定很弱

ranning

C: 只有当新开矿的人均output大于其它矿的平均output时，才会使得总的平均output > it actually was

Hence C 错