Take a look at the heads of the animals. Are they all the same? Yes and no. Yes, each animal has ears, eyes, a mouth, and a nose. But no, they don’t have the same kind of mouth and nose. Why? Because, through many thousands of years, the animals’ bodies slowly changed. The giraffe is a good example of evolution. With its long neck, it reaches food at the top of trees. Then it pulls the branches to its mouth. Finally, with special teeth like a comb, it can quickly strip the leaves off the branches.
让我们来看一下这些动物的头部。它们全都是一样的吗？一样，但又不一样。说它们一样，是因为每种动物都有耳朵、眼睛、嘴巴和鼻子。说它们不一样，是因为它们的嘴巴和鼻子长得各不相同。这是为什么呢？原来，历经千万年的演变，动物的身体已慢慢发生了变化。长颈鹿就是动物进化的一个好例子。它的长脖子使它可以够到树顶上的食物，然后将树枝拉向嘴边，最后，它可以用自己长得很特别的、像梳子一样的牙齿很快地将叶子从树枝上扒个精光。
Dogs and rabbits have highly developed senses of smell and touch. They communicate with each other by using pheromones (scent from their bodies). And the sensitive hairs on their faces help the animals to find their way in the dark.
狗和兔子有着高度发达的嗅觉和触觉。它们通过信息素（即身体的气味）相互交流，它们面部敏感的毛发则使它们在黑暗中也不会迷路。
The hippopotamus also uses its mouth for communication. Here, with mouth wide open, it is warning another hippo1 and saying “Go away!”
河马也用它们的嘴来进行交流。看，这张张开的大嘴，是在警告另一只河马，示意它“快走开！”
Whose mouths are these? Can you guess? They all belong to carnivores.
这些都是什么动物的嘴？你能猜到吗？对了，它们都是食肉动物的嘴。
Lions communicate with their whole bodies, but especially with their faces. They can show anger, fear, and contentment.
狮子用整个身体来传达信息，不过最主要还是通过面部。它们能表达愤怒、恐惧和满足。
Lions also make different noises that mean different things. A snarl means they are attacking another animal, or defending their cubs. A roar keeps lions in touch over long distances. And a roar can mark territory.
狮子还通过发出不同的声音来表达不同的意思。咆哮意味着它们将要攻击其他动物，或是保护它们的幼仔。吼叫声使相距遥远的狮子彼此保持联系，而且还能划分各自的领地。
Lions have very good noses. Their highly developed sense of smell gives them information about animals nearby, especially other lions and lionesses.
狮子有着非常灵敏的鼻子。高度发达的嗅觉使它们能了解到附近动物的情况，尤其是其他雄狮和母狮的情况。
A long time ago the “king of beasts” lived in northern India, the Middle East, and even in Europe. Today, the lion lives only in Africa, and in one nature reserve in north-west India. In fact, there are very few lions left in the world. In the past, hunters killed them and kept their heads and skins as trophies. Nowadays, lion hunting is strictly controlled.
很久以前，“兽中之王”狮子生活在印度北部、中东，甚至欧洲一带。然而今天，狮子却仅存于非洲以及印度西北部的一个自然保护区内。事实上，世界上的狮子已经为数不多了。在过去，捕猎者杀死它们，将它们的头和皮毛当作战利品。如今，猎杀狮子的行为受到严格的控制。liuxuepaper.com
The frog is an amphibian, which means it can live on land and in water. It is a carnivore, but it doesn’t have any teeth. This is because frogs catch mainly soft animals like worms and snails. So why is a frog’s mouth so big? Perhaps because it is like a sound-box, adapted for2 communication. Frogs can “sing” and make many different sounds.
青蛙属于两栖动物，也就是说它既能生活在陆地上也能生活在水里。它是一种食肉动物，却没有牙齿。这是因为青蛙的捕食对象主要是软体动物，比如蠕虫和蜗牛。那么，青蛙的嘴为什么如此之大呢？或许因为它的嘴要充当音箱的角色，以适合于沟通交流的需要。青蛙能够“唱歌”，并发出各种不同的声音。
This male frog on this leaf is calling to the female frogs in the water. He attracts them by croaking. But he is not alone. Hundreds of other male frogs are croaking with him. They sound like small motorbike engines.
这只趴在荷叶上的雄蛙正在召唤水里的雌蛙们，它通过呱呱声吸引对方。它可不是在独唱，有数以百计的雄蛙都在和它一起“呱呱”高歌呢。它们叫起来简直就像一个小型摩托车的引擎。