But shooting, including the sound of heavy weaponry, was later heard in the center of the copper mining city.

后来这座铜矿城市的中心发出了枪声，包括重型武器的声音。

It was such a pipe that made Johannesburg the most productive diamond mining city in the world, but there may be others even bigger that we don't know about.

正是由于这类岩筒，南非成了世界上出产钻石最多的国家，但很可能别的国家蕴藏量还要丰富，我们现在还不知道。