For most people the sea was remote, and with the exception of early intercontinental travelers or others who earned a living from the sea, there was little reason to ask many questions about it, let alone to ask what lay beneath the surface. The first time that the question What is at the bottom of the oceans? had to be answered with any commercial consequence was when the laying of a telegraph cable from Europe to America was proposed. The engineers had to know the depth profile of the route to estimate the length of cable that had to be manufactured.
注：1. remote 遥远的
2. and with...多重复合句
3. intercontinental 洲际的 (Inter 在之间，continent 大洲)
4. let alone 更不用说
5. first time 由不感兴趣转折到感兴趣 ，谓语是 was
6. 第二句that引导同位语从句，when引导表语从句，整句意思为 当有人基于商业目的`建议在美国和欧洲之间铺设电报电缆的时候，人们才提出问题：海底是什么?
e 路线 router 路由器
