Some animals that cannot see can still tell the difference between light and darkness, while others can react to chemicals, which is something like smelling and tasting. However, there may be a sense that we know nothing about, for otherwise it is very hard to explain how birds, animals and even insects and fish manage to travel long distances without losing their way.
Only man can tell his companions exactly what he wants, for he has the wonderful gift of speech; but many of the larger animals can show that they are hungry or frightened or pleased by making sounds that we have learned to recognize, such as a roar. Even man still uses animal-like sounds when he laughs or sighs.
Some animals can get further than these simple noises. For instance, a bird song is much more elaborate, for it tells other males to keep away, while at the same time inviting a female to come closer. Birds have other calls which warn of danger or help to keep the flock (鸟群) together. Of course, a parrot does not understand what it is saying when it imitates the human voice.
正确答案：一些没有视觉的动物，仍能辨别出光线和黑暗的不同，而其它一些动物能对化学物质做出反应，就如同有味觉和嗅觉一样。然而，一定存在一种我们不知道的感觉。因为如果不是这样的话，就很难解释为什么鸟、动物甚至昆虫和鱼能旅行很长的距离而不迷路。只有人能确切地告诉他的同伴他想要什么，因为人有奇妙的语言天赋，但是许多大一些的动物能够发出我们已经学会辨别的声音如吼叫来表达它们的饥饿、受惊或高兴。甚至人类在笑或叹息的时候仍然使用像动物的声音。一些动物能发出比这些简单的声音更复杂的声音，例如，鸟儿的歌声就更复杂精细，因为它能告诉其它雄性鸟离开，同时邀请雌性鸟儿靠近。鸟儿有时发出声音警告危险或使鸟群紧密结合。当然，当鹦鹉模仿人发声的时候并不理解其中的含义。
相关内容：
（责任编辑：中大编辑）
