8 A2 swing, slither, swim

CHAPTER 1 How Many ways Do Animals Move? ANIMALS MOVE TO FIND FOOD AND STAY SAFE. SOME ANIMALS USE THEIR LEGS; SOME USE THEIR ARMS; AND SOME USE THEIR WHOLE BODIES TO MOVE. THERE ARE MANY KINDS OF ANIMAL LOCOMOTION. Many animals move on two or more legs. A penguin walks on two legs. A horse runs on four legs. A grasshopper hops on six legs. A centipede walks on many small legs, and it can even run if there is danger. Animals can also move quickly with their arms. A monkey uses its arms to climb trees and look for food. Birds use their wings to fly. Fish can swim thanks to their fins.

第一章动物有几种移动方式？ 动物移动是为了寻找食物和保持安全。 有些动物用腿；有些人用胳膊；有些人用整个身体来移动。 动物的运动有很多种。 许多动物用两条或多条腿移动。 企鹅用两条腿走路。 马用四条腿跑。 蚱蜢用六条腿跳跃。 蜈蚣用许多细小的腿走路，如果有危险，它甚至可以跑。 动物也可以用手臂快速移动。 猴子用它的手臂爬树和寻找食物。 鸟用翅膀飞翔。 鱼能游泳多亏了它们的鳍。

What about animals that don't use their arms and legs to move? How do they move? Well, a snake doesn't have arms or legs, but it can move very fast. It uses its whole body. A pangolin has arms and legs, but sometimes it doesn't use them to move. If the pangolin is in danger, it becomes a ball and rolls away to be safe. Isn't it amazing how many kinds of locomotion there are? Each kind of animal has its own special way of moving.

那些不用胳膊和腿移动的动物呢？ 它们是如何移动的？嗯，蛇没有胳膊和腿，但它可以移动得非常快。 它使用整个身体。穿山甲有胳膊和腿，但有时它不用它们来移动。 如果穿山甲有危险，它就会变成一个球，滚开以保安全。 运动的种类之多是不是很神奇？ 每种动物都有自己独特的移动方式。

CHAPTER 2 Legs NATURE SAYS "MOVE IT OR LOSE IT!" BUT LOSE WHAT? YOUR LIFE! Animals often have to move fast to get away from danger. If they can run fast, they can get away and be safe. Is it better to have four legs or two when you want to run away from danger? Horses run with four legs and they can run very fast. However, their legs are very slim, and they break easily. Also, horses get most of the sleep that they need standing up. So if a horse breaks its leg, this makes it very difficult for the leg to get better.

第二章腿大自然说：“不动就失去它！”但是失去什么呢？ 你的生活!动物通常必须迅速行动以逃离危险。 如果他们能跑得快，他们就能逃脱并获得安全。 当你想逃离危险时，是四条腿好还是两条腿好？ 马用四条腿跑，它们跑得很快。 然而，他们的腿很细，很容易折断。 而且，马需要的大部分睡眠都是站着睡的。 所以如果一匹马摔断了腿，它的腿就很难好起来。

Penguins have two legs, but they can't run fast. In one hour, penguins can only walk about three kilometers across the ice of Antarctica. Penguins are birds, but they can't fly! But luckily for penguins, they can swim very well to get away from danger. Like ducks, penguins have wide feet. This helps them swim fast. Some penguins can swim at a speed of 24 kilometers an hour! Ostriches are the largest and heaviest birds in the world. Like penguins, ostriches cannot fly, but they can walk and run fast. In fact, they can run as fast as 70 kilometers an hour. Ostriches' legs are the longest of all birds, and they are very strong. Believe it or not, an ostrich can kill a person with one kick!

企鹅有两条腿，但它们跑不快。 在一小时内，企鹅只能在南极洲的冰面上行走大约三公里。 企鹅是鸟，但是它们不会飞！但幸运的是，企鹅可以很好地游泳以逃离危险。 和鸭子一样，企鹅的脚也很宽。 这有助于它们游得快。 有些企鹅能以每小时24公里的速度游泳！鸵鸟是世界上最大最重的鸟类。 像企鹅一样，鸵鸟不能飞，但它们能很快地走和跑。 事实上，它们的时速可达70公里。 鸵鸟的腿是所有鸟类中最长的，而且它们非常强壮。 信不信由你，鸵鸟一脚就能杀死一个人！

Kangaroos also have powerful legs. Their big back feet and long back legs are much larger and more powerful than their front feet and legs. This means that kangaroos can travel very fast, but they don't run. They hop. Kangaroos usually hop at speeds of 25—48 kilometers an hour. Grasshoppers, like all insects, have six legs. They use their powerful back legs to hop very far. A grasshopper that is 2.5 centimeters long can hop 50 centimeters: That's twenty times its size! So, the grasshopper can move away from danger quickly. Grasshoppers also use their legs to make music! This tells other grasshoppers that danger is near.

袋鼠也有有力的腿。 它们的大后脚和长后腿比前脚和前腿更大更有力。 这意味着袋鼠可以走得很快，但它们不会跑。 他们跳。袋鼠通常以每小时25-48公里的速度跳跃。 蚱蜢，像所有的昆虫一样，有六条腿。 它们用有力的后腿跳得很远。 一只2.5厘米长的蚱蜢可以跳50厘米：那是它的20倍大！因此，蚱蜢可以迅速逃离危险。 蚱蜢也用它们的腿来制作音乐！这告诉其他蚱蜢危险临近了。

Centipedes have even more legs than insects do. The word centipede means "one hundred feet," but some centipedes have only thirty feet, whereas others have three hundred! Their many legs help them move away from danger. Millipedes have more legs than centipedes, but millipedes move slowly because they have short legs that can't go very far. Centipedes also have two larger, special legs that they use to catch and eat their food— like teeth! All of the animals in this chapter use their legs for locomotion. Some animals have more legs than others, but more does not always mean better. Each animal has its special way of moving to be safe.

蜈蚣的腿甚至比昆虫还多。 蜈蚣这个词的意思是“一百英尺”，但是有些蜈蚣只有三十英尺，而有些蜈蚣有三百英尺！它们的长腿帮助它们远离危险。 千足虫比蜈蚣有更多的腿，但千足虫移动缓慢，因为它们的腿很短，不能走很远。 蜈蚣还有两条更大、更特殊的腿，它们用来捕捉和吃食物——就像牙齿一样！本章中所有的动物都用腿来移动。 有些动物的腿比其他动物多，但多并不意味着更好。 为了安全，每种动物都有自己独特的移动方式。