When you take a walk in any city, y

When you take a walk in any city, you often see a lot of people walking dogs. It is still true that a dog is the most useful and faithful animal in the world, but the reason why people keep a dog has changed. In the old days people used to train dogs to protect(保护) themselves against attacks by other beasts. Later they came to realize that a dog was not only useful for protection but willing to obey his master. For example, when people used dogs for hunting, the dogs would not eat what was caught without permission.
These days people in the city need not protect themselves against attacks from animals. Why do they keep dogs, then? Some people keep dogs to protect themselves from robbery（抢劫）. But the most important reason is for companionship. For a child, a dog is a best friend when there are no friends to play with. For young couples, a dog is their child when they have no children. For old couples, a dog is also their child when their natural children have grown up. So the main reason why people keep dogs has changed from protection to friendship.

結果 (中文) 1:

当你走在任何城市时，你经常看到很多人遛狗。仍然是一条狗是世界上最有用最忠实的动物，但人们为什么养狗的原因现在已经改变。古时候人们用来训练狗到 protect(保护) 自己攻击由其他野兽。后来，他们意识到一只狗是不仅用来保护自己，愿意服从他的主人。例如，当人们用于狩猎的狗，狗不会吃什么被抓获时没有权限。这些天在城市的人不需要保护自己从动物的攻击。他们然后养狗?有些人养狗来保护自己免受 robbery(抢劫)。但最重要的原因是为了友谊。对于一个孩子，一只狗是最好的朋友，有没有朋友可以一起玩的时候。对于年轻夫妇来说，狗是他们的孩子，当他们有没有孩子。对于老年夫妇来说，一只狗也是他们的孩子当他们自然的孩子已经长大了。因此从保护到友谊，改变了人们为什么养狗的主要原因。

結果 (中文) 3:

当你在任何一个城市散步时，你经常看到很多人在散步。事实上，狗是世界上最有用和最忠实的动物，但人们养狗的原因却改变了。在过去人们用来训练狗来保护自己（保护）攻击其他动物。后来他们意识到，一只狗不仅是有用的保护，但愿意服从他的主人。例如，当人们用狗来打猎时，狗不会吃东西，没有被允许的东西。这些天里的人不必保护自己免受动物的攻击。他们为什么养狗呢？一些人养狗来保护自己免受抢劫（抢劫）。但最重要的原因是陪伴。对于一个孩子，一只狗是一个最好的朋友，当有没有朋友玩。对于年轻夫妇，一只狗是他们的孩子时，他们没有孩子。对于老夫妇，一只狗是他们的孩子，当他们的孩子长大了。所以人们养狗的主要原因是从保护到友谊。