The first time that 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.
【译文】当有人建议铺设一条从欧洲到美洲的海底电报光缆的时候，出于商业动机，人们才不得不首次回答这个问题“海底有什么东西”。
【析句】本句话的难点在于主从句成分的区分。主句为The first time was when the laying…was proposed，when引导表语从句，而that question had to be answered with…则是定语从句修饰the first time.
