Over the next twenty-five years, six independent deep underground lines were constructed.

在接下来的25年里，又建造了6条独立的地下线路。

So, they tried something that was relatively  new and innovative for the time: they ran the line underground.

因此，他们尝试了当时相对较新和创新的做法：将线路运行在地下。

Well, I'm happy to report that the power company have agreed to move the power lines underground at a cost of $800, 000.

我很高兴地告诉大家，电力公司已经同意耗资800,000美元将这些电线转移到地下。

The best solution here is to bury the power lines underground, but that's a huge project, and no one's jumping at the chance to pay for it.

最好的解决办法就是将这些电线埋在地下铺设，但这是一项大工程，没有人会为了抓住这个机会而承担此项费用。

The Metropolitan reports show that they spent anywhere from $500,000 to $600,000 a mile building underground trolley lines which, at their own extravagant estimate, should have cost only $150,000.

他们每英里花费 500,000 美元到 600,000 美元建造地下有轨电车线路， 根据他们自己的奢侈估计， 这些线路的成本应该仅为 150,000 美元。