He's got a whale of a tail to tell about the time he took the underground overground and wound up grounded to an undersea creature.

好比他得了条鲸鱼尾，会指示他何时游走于水上水下，缠住其它海洋生物。

It's short for Docklands Light Railway. Actually, it it an overground system connecting East London to the London Underground network.

它是港区轻轨的简称。实际上，它是一个连接东伦敦和伦敦地铁网络的地上系统。

Most major cities already have some form of  city-wide transit network, whether it's a subway or an effective overground rail system.

主要城市已经拥有某种形式的全市交通网络，无论是地铁还是有效的地上铁路系统。