邮递人员听见了小鸭子的叫声，并被允许打开箱子喂这些幼雏食物和水。
Postal workers heard the ducklings and got permission to open the box to get the babies some food and water.
每只鸭子叫一次或者多次，叫声此起彼伏。
Each duck makes the sound one or more times, one after another.
如果一个动物很像鸭子，叫声和鸭子一样，走路也像鸭子，同时有足够的证据显示它就是鸭子，那我们就叫它鸭子。
If something looks like a duck, sounds like a duck, walks like a duck and there is enough evidence to prove it's a duck, then that's what we'll call it.