Where do we find the material strong enough yet lightweight enough to act as a cable or track?

我们在哪里可以找到足够坚固且足够轻的材料来充当电缆或轨道呢？

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'we were going out to track down two bank robbers when the cable came,' he replied.

电报来的时候，我们正在追两个抢银行的抢匪，'他答道。

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The structure of this system is demanded mainly from carry cable, track cable and hanger. it is a strong geometry nonlinear structure.

该系统的承重结构主要是由承重索、轨索、吊索组成的一个索网结构，具有较强的几何非线性。

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First of all, every commuter rail system has full time maintenance crews, and they always have plenty of work: changing lightbulbs in the tube, fixing a signal that got bumped, replacing an on-track communication cable that was vibrated out of place and smashed, etc.

FORBES: Why Does BART Need To Do Nightly Maintenance?

City officials acknowledge that the open air cable cars, which ply only eight miles of track, produce a disproportionate amount of accident-related costs.

NPR: San Francisco Cable Car Accidents Costs Millions