求翻译：举一个例子：我国的木兰溪，在50年代初本是一个清澈见底的河流，但现在它已是鱼虾绝迹的污河，又为我们的地球母亲添多一道疤痕。这，不是给人类重重地敲响了警钟吗？是什么意思？

As an example: China's Mulan, in the early 1950s, this is a crystal clear river, but now it is extinct fish river pollution, but also add to our Mother Earth more than a scar. This is not to human beings has sounded the alarm heavily it?

To cite an example: In my country the Mulan River in early 1950s, this is a clear see the bottom of the river, but now it is the sewage river fish and shrimps, but also for our mother earth Tim one more scar. This is not to the human race fell, sounded the alarm?

Cites an example: Our country's wooden Lanxi, in the beginning of the 50's originally is clear enough to see bottom rivers, but now it already is the dirty river which the fish and shrimp vanished, also added many scar for ours Earth mother.This, was not layer on layer has sounded the alarm bell for

Give an example: Mulan XI, in the early 50 's was a Crystal clarityof rivers, but now it's pollution River of fish died out, and for our mother earth adds more scar. This is not strongly cautions you to mankind?