A CROW perishing with thirst saw a pitcher, and hoping to find water, flew to it with delight. —-
一只渴死的乌鸦看见一个瓶子，希望能找到水，欢喜地飞了过去。 —-

When he reached it, he discovered to his grief that it contained so little water that he could not possibly get at it. —-
当它飞到时，发现里面只有那么一点水，根本无法喝到。 —-

He tried everything he could think of to reach the water, but all his efforts were in vain. —-
它想尽了办法去够到水，但所有的努力都白费。 —-

At last he collected as many stones as he could carry and dropped them one by one with his beak into the pitcher, —-
最后，它收集了尽可能多的石头，用喙一个一个地放进瓶子里， —-

until he brought the water within his reach and thus saved his life.
直到把水够到口，从而救了自己的命。

Necessity is the mother of invention.
需求是发明的动力。