许多家庭当他们有时间的时候会选择带他们的孩子去动物园玩，因为这样可以拓宽孩子们的视野并获得有关动物的知识。

A lot of families will choose to take their children to the zoo when they have time, because they can broaden the children's vision and gain the knowledge about the animals. But the problem is that some parents give the food the children and admit them to throw it to the animals. It is harmful to the animals. We should behave ourselves. 
许多家庭当他们有时间的时候会选择带他们的孩子去动物园玩，因为这样可以拓宽孩子们的视野并获得有关动物的知识。但问题是，有些父母给孩子们食物，并允许他们向动物投放食物。这样做对动物是有害的。我们应该自律。