21 Growing Up From Baby to Adult

CHAPTER 1 The Start of Life HOW DOES LIFE START? IS IT THE SAME FOR PEOPLE AND ANIMALS? Some animals, like birds and alligators, start life inside an egg. But many animals carry their babies in their bodies. For the first nine months before humans are born, they grow inside their mothers. Baby cats are inside their mothers for only two months. A female lion carries her baby for about four months. And an elephant is inside its mother for 22 months. The mother is usually the most important parent. The baby is safe inside her. It takes food from her. The mother often looks after the baby after it is born, too. But sometimes the father is more important. For example, the female seahorse puts as many as 1,500 eggs in the male seahorse's body. The father then carries the eggs for two to four weeks. The eggs get food from his body until they hatch. Now the baby seahorse can look after itself. Dad's job is finished! The male sea catfish is important, too. After the female puts her eggs on the sea floor, the male takes them in his mouth. And they stay there for about two months. Then, the eggs hatch, and the baby fish swim out to start their lives.

第一章生命的开始生命是如何开始的？ 人和动物是一样的吗？ 有些动物，比如鸟类和短吻鳄，是在蛋里开始生命的。 但是许多动物把它们的宝宝放在身体里。 在人类出生前的前九个月，他们在母亲体内成长。 小猫在妈妈体内只有两个月的时间。 雌狮的孕期大约为4个月。 大象在妈妈肚子里要待22个月。 母亲通常是最重要的父母。 孩子在她肚子里很安全。 它从她身上拿走食物。孩子出生后，妈妈也经常照看孩子。 但有时父亲更重要。 例如，雌性海马会在雄性海马体内产下多达1500个卵。 然后父亲带着卵两到四周。 蛋从他的身体里获取食物直到孵化。 现在小海马可以照顾自己了。 爸爸的工作完成了！雄性海鲶鱼也很重要。 当雌性把卵放在海底后，雄性就把它们叼进嘴里。 他们在那里呆了大约两个月。 然后，卵孵化，幼鱼游出来开始它们的生活。

CHAPTER 2 Babies ALL BABIES NEED THEIR PARENTS TO LOOK AFTER THEM. OR DO THEY? Most new baby sharks can swim and look for food. But great white shark babies start finding food for themselves before they are born. They hatch out of eggs inside the mother and get hungry. They eat other eggs, and sometimes they eat their brothers and sisters! Adult snakes don't look after their babies. Snakes look after themselves from day one. The African black mamba is one of the world's most dangerous snakes. A baby black mamba is as dangerous as an adult. It can catch and eat small animals as soon as it hatches. A zebra baby can walk about 15 minutes after it's born. After one hour, it can run. This is very important. Lions love to eat baby zebras. But baby zebras can run and stay near their mother and the other adult zebras. Then they are safer. Other animals can do very little when they are born. The kangaroo is born after only 35 days inside its mother. The baby is very small: two centimeters long. That's smaller than your eye! It climbs into its mother's pouch to be safe, and it stays there for 7 to 10 months!

第二章婴儿所有的婴儿都需要父母照顾。 他们会吗？大多数新出生的小鲨鱼会游泳和寻找食物。 但大白鲨宝宝在出生前就开始为自己寻找食物了。 它们从母亲体内的蛋中孵化出来，然后饿了。 它们吃别的蛋，有时还吃自己的兄弟姐妹！成年蛇不照顾它们的幼蛇。 蛇从第一天起就会照顾自己。 非洲黑曼巴是世界上最危险的蛇之一。 小黑曼巴和成年黑曼巴一样危险。 它一孵出来就能抓小动物吃。 斑马宝宝出生后大约15分钟就能走路了。 一个小时后，它就能跑了。 这一点非常重要。狮子喜欢吃小斑马。 但小斑马可以跑，并留在它们的母亲和其他成年斑马附近。 这样他们就更安全了。其他动物出生时能做的事情很少。 这只袋鼠在妈妈肚子里35天后就出生了。 这个婴儿很小，只有两厘米长。 那比你的眼睛还小！为了安全，它会爬进妈妈的育儿袋里，在那里呆上7到10个月！

Baby birds can't fly, and their parents bring them food every day. When they grow, they start trying to fly. Sometimes the mother helps. She stands near the nest with some food. The small birds try to get the food, but they often fall to the ground. After many accidents, they learn to fly. Many baby animals really need their parents. So what if their parents die? Many adult animals look after the babies of another animal of the same kind. But dogs sometimes look after other kinds of animals, like kittens, baby chickens, or even baby tigers. And what about us? There are about 370,000 human babies born every day somewhere in the world. Babies can't walk, talk, or see very well. (Some people think babies are good swimmers, but this isn't right. If you put them in water, they move their arms and legs, but they aren't really swimming.) A human baby dies very quickly if its parents or other adults don't look after it. In the first two years, babies learn many things. At 8 to 12 months, they usually say their first word. Between 9 and 18 months, they start walking. But they're not like zebras. They will need the help of adults for many years to come!

幼鸟不会飞，它们的父母每天都给它们带食物。 当它们长大后，它们开始尝试飞翔。 有时妈妈会帮忙。 她拿着一些食物站在鸟巢附近。 小鸟试图得到食物，但他们经常掉到地上。 经过多次事故，他们学会了飞行。 许多小动物真的需要它们的父母。 如果他们的父母去世了呢？ 许多成年动物会照顾同类动物的幼崽。 但狗有时也会照顾其他种类的动物，比如小猫、小鸡，甚至是老虎。 那我们呢？世界上每天大约有37万婴儿出生。 婴儿不能走路，不能说话，也看不清楚。 (有些人认为婴儿擅长游泳，但这是不对的。 如果你把它们放在水里，它们会移动胳膊和腿，但它们并不是真的在游泳。)如果父母或其他成年人不照顾，人类婴儿很快就会死亡。 在头两年，婴儿学习很多东西。 在8到12个月大的时候，他们通常会说第一个单词。 在9到18个月之间，他们开始走路。 但它们不像斑马。 在未来的许多年里，他们都需要成年人的帮助！

CHAPTER 3 Adolescence ADOLESCENCE IS A DIFFICULT TIME, BUT WHY? Let's look at humans first. Between the ages of 10 and 17, girls usually grow about 23 centimeters and boys about 38 centimeters. Girls usually get heavier by about 17 kilograms and boys by about 24 kilograms. Teenagers can grow very quickly in a short time. This is called a growth spurt. In a growth spurt, a teenager can grow more than 12 centimeters in one year. In girls, these growth spurts start earlier than in boys. This is why girls of 12 are often taller than boys of the same age. And what about inside their heads? Do teenagers think differently from adults? One part of the brain is called the amygdala. This makes us feel angry, happy, or sad. Another part of the brain, called the cortex, helps us make good decisions. In adolescents, the cortex is small, so they use the amygdala much more. Teenagers often get angry or sad very quickly. They often don't make good decisions and do dangerous things. Between the ages of 16 and 19, more people die in accidents than at any other time.

第三章青春期青春期是一个艰难的时期，但是为什么呢？ 让我们先看看人类。 在10到17岁之间，女孩通常长23厘米，男孩长38厘米。 女孩通常增重约17公斤，男孩增重约24公斤。 青少年可以在短时间内迅速成长。 这被称为生长突增。 在一个生长突增时期，一个青少年可以在一年内长12厘米以上。 在女孩中，这些生长突增开始得比男孩早。 这就是为什么12岁的女孩通常比同龄的男孩高。 那么在他们的头脑里呢？ 青少年的想法和成年人不同吗？ 大脑的一部分叫做杏仁核。 这让我们感到愤怒、快乐或悲伤。 大脑的另一部分，叫做皮层，帮助我们做出正确的决定。 在青少年中，大脑皮层很小，所以他们更多地使用杏仁核。 青少年通常很快就会生气或悲伤。 他们经常不能做出正确的决定，做危险的事情。 在16岁到19岁之间，死于事故的人比任何时候都多。

Most animals start adolescence at a younger age than humans. Elephants start adolescence when they stop drinking their mother's milk, usually between 5 and 10 years old. Adolescence usually finishes when they are 17. During adolescence, a male elephant leaves its mother and goes with a group of other young males. But a female elephant stays with her mother. Male lions start to grow a lot of hair on their heads when they are about 18 months old. This is called a mane. If a lion has a very big mane, it shows that he is a very important lion. Adolescence in cats starts at seven months and ends at 12 months. At this time, female cats start looking for male cats to have babies with. And male cats leave a strong smell in the places where they live. This tells other male cats to stay away! Dog adolescence is from six months of age. At about the same time, puppies also grow new adult teeth. This makes them feel bad, and they often chew things. This can be a very bad time for you, too, if you have a dog. The second teeth are strong, and puppies chew everything!

大多数动物比人类更早进入青春期。 大象通常在5到10岁之间停止喝母象的乳汁，开始进入青春期。 青春期通常在17岁时结束。 在青春期，一头公象离开它的母亲，和一群其他年轻的公象一起去了。 但是雌象和妈妈呆在一起。 雄性狮子在大约18个月大的时候，头上开始长出很多毛发。 这叫做鬃毛。如果一头狮子有非常大的鬃毛，那就表明它是一头非常重要的狮子。 猫的青春期从7个月开始到12个月结束。 在这个时候，母猫开始寻找公猫来生孩子。 公猫在它们生活的地方会留下强烈的气味。 这告诉其他公猫远离！狗的青春期从6个月大开始。 大约在同一时间，小狗也长出新的成年牙齿。 这让他们感觉很糟糕，他们经常咀嚼东西。 如果你有一只狗，这对你来说也是一个非常糟糕的时间。 第二颗牙齿很强壮，小狗什么都能咬！

CHAPTER 4 Becoming an Adult IT'S TIME TO GROW UP. People stop growing at different times. So when does adolescence end and adulthood begin? In most countries, you're an adult when you're 18 years old. But in some countries, adulthood starts earlier or later. In Cuba, for example, you're an adult at 16, but in Egypt, you don't become an adult in all ways until you're 21. Why is this important? Because when you're an adult, you can do many things you couldn't do before. For example, you can vote, get married, or drive a car. In many countries, when somebody becomes an adult, they have a party. But in some parts of the world, people do dangerous things. On the small South Pacific island of Vanuatu, young men jump from a high place, 30 meters above the ground. They put a long, strong rope around their leg. It stops them from hitting the ground and dying. But it's still dangerous. In Australia, adolescent Aboriginal boys have to live alone for as long as six months in the Australian outback. The young men have to find food and water. It's very hot and dry in the outback and there are dangerous animals, like snakes. In the past, most Aboriginal boys did this, but not many do it now. In one part of Ethiopia, before a young man can get married, he has to run on top of some cows and not fall down. This shows he is leaving childhood behind and starting life as an adult.

是该长大的时候了。 人在不同的时间停止生长。 那么青春期何时结束，成年期何时开始呢？ 在大多数国家，18岁就是成年人。 但在一些国家，成年期开始得或早或晚。 例如，在古巴，你16岁就可以成为成年人，但在埃及，你要到21岁才能成为成年人。 为什么这很重要？因为当你是一个成年人，你可以做很多你以前不能做的事情。 例如，你可以投票、结婚或开车。 在许多国家，当某人成年时，他们会举行聚会。 但在世界上的某些地方，人们会做危险的事情。 在南太平洋的瓦努阿图小岛上，年轻人从离地30米的高处跳下。 他们在腿上套了一根又长又结实的绳子。 它可以防止它们撞到地面而死亡。 但这仍然很危险。在澳大利亚，青春期的土著男孩必须在澳大利亚内陆独自生活长达六个月。 年轻人必须找到食物和水。 内陆非常炎热干燥，有危险的动物，比如蛇。 过去，大多数土著男孩都这样做，但现在很少有人这样做了。 在埃塞俄比亚的一个地区，年轻男子在结婚前必须骑在牛身上奔跑，不能摔倒。 这表明他正在离开童年，开始作为一个成年人的生活。