Part 4

A balanced diet Your body turns the food you eat into energy. There are five main food groups, and you need to eat a different amount of food from each of them in order to stay healthy. Carbohydrates Carbohydrates are found in foods such as potatoes, pasta, bread, and rice. They are the body's main source of energy. Fruit and vegetables These foods contain many vitamins and minerals, which help your body fight infections. Different colored fruit and vegetables have different benefits. Keeping healthy Your body needs energy to keep it working well. The foods you eat and how much you move your body can affect your energy levels throughout the day. Your body is two-thirds water! That's why you should drink a lot of water every day. Protein Protein builds muscles and repairs cells. Meat, fish, eggs, beans, and lentils are good sources of protein. Some protein-rich foods, like oily fish, also help keep the heart healthy. Dairy Milk, cheese, and yogurt contain calcium, which makes bones and teeth strong. Dairy foods like these also contain protein and give you energy. Fat A small amount of fat is good for you. Sources of healthy fats include olive oil, avocados, nuts, and seeds. Feel good Your brain releases chemicals that make you feel good. More energy Your lungs and heart work harder, delivering more oxygen to the body. Socializing Exercise is a good way to have fun and spend time with friends. Better concentration Increased blood flow to the brain makes you more alert and awake. Improved sleep Exercising during the day can help you get a better night's sleep.

均衡饮食 你的身体会把吃进去的食物转化成能量。 主要分为五大食物组别，为了保持健康，你需要从每个组别摄入不同量的食物。 碳水化合物 土豆、意面、面包、米饭这类食物都含有碳水化合物。 它们是身体最主要的能量来源。 蔬菜水果 这类食物含有多种维生素和矿物质，能帮你的身体对抗感染。 不同颜色的蔬菜水果有不同的好处哦。 保持健康 你的身体需要能量来维持正常运转。 你吃的食物和运动量，会影响你一整天的能量水平。 你的身体三分之二都是水！ 这就是你每天要喝很多水的原因哦。 蛋白质 蛋白质能强健肌肉、修复细胞。 肉类、鱼类、鸡蛋、豆子和小扁豆都是优质的蛋白质来源。 有些富含蛋白质的食物，比如多脂鱼，还能帮助心脏保持健康。 奶制品 牛奶、奶酪和酸奶都含有钙质，能让骨骼和牙齿更强健。 这类奶制品也含有蛋白质，还能为你提供能量。 脂肪 摄入少量脂肪对身体是有益的。 健康脂肪的来源包括橄榄油、牛油果、坚果和种籽。 心情愉悦 你的大脑会释放让你感觉舒服的化学物质。 能量更充足 你的肺和心脏会更努力工作，给身体输送更多氧气。 增进社交 运动是玩乐、和朋友相聚的好方式。 注意力更集中 流向大脑的血流量增加，会让你更警觉清醒。 改善睡眠 白天运动能帮你晚上睡得更香。

Sleep When you are asleep, your body has a chance to rest and your brain can sort through information collected from the day's events. Most people spend one-third of their lives sleeping! Benefits of sleep It is important to get enough sleep each night to keep you healthy. Without it, you become tired and irritable. Your body starts to slow down and you are more likely to get sick. Growth During sleep, your body releases a growth hormone. Memory Your brain logs the day's important information in your memory. Mood Good quality sleep lifts your mood. Healing Your body repairs and renews cells when you are asleep. Energy After a restful sleep, you wake up with more energy. Sleep patterns There are different stages of sleep, split into REM (rapid eye movement) and non-REM sleep. You cycle through these stages a number of times during the night. Sleep starts off deep and gets lighter as the night progresses. REM During REM sleep, your eyes move very quickly under your eyelids. This is when dreams take place. Light You move around a lot more and are easier to wake during light sleep than in deep sleep. Deep Your body grows and repairs its cells during the deepest stage of sleep. An average 6–9 year-old needs 9–12 hours of sleep a night. Try to go to sleep at the same time every day. Keep your bedroom dark and cool. Wear comfortable clothes! Avoid food and drinks containing caffeine, such as chocolate and carbonated drinks. Stop looking at screens two hours before bedtime. Tips for good sleep When it gets dark, your body realizes it is time to sleep. There are certain things you can do to help you get a good night's rest.

睡眠 当你睡着时，身体得到休息机会，大脑还会整理一整天收集到的信息。 大多数人一生中有三分之一的时间都在睡觉哦！ 睡眠的好处 每晚睡够对保持健康非常重要。 如果睡不够，你会变得疲惫又易怒。 你的身体运转会变慢，你也更容易生病。 生长 睡觉时，你的身体会释放生长激素。 记忆 大脑会把白天重要的信息存入你的记忆。 情绪 优质的睡眠能让你的心情更好。 修复 睡觉时你的身体会修复和更新细胞。 能量 舒舒服服睡一觉后，你醒来会更有活力。 睡眠模式 睡眠分为不同阶段，分为快速眼动睡眠（REM）和非快速眼动睡眠。 一整夜，你的睡眠会在这些阶段之间循环好几次。 睡眠一开始深度较深，随着夜晚推移逐渐变浅。 快速眼动睡眠 在快速眼动睡眠阶段，你的眼球会在眼睑下快速转动。 做梦就发生在这个阶段。 浅睡 和深度睡眠相比，浅睡时你动得更多，也更容易被叫醒。 深度睡眠 在最深的睡眠阶段，你的身体会完成生长和细胞修复。 6到9岁的孩子平均每晚需要睡9到12小时。 试着每天在固定时间上床睡觉。 让你的卧室保持昏暗和凉爽。 穿舒适的衣服睡觉哦！ 不要吃含咖啡因的食物和饮品，比如巧克力和碳酸饮料。 睡觉前两小时就不要看电子屏幕了。 好睡眠小贴士 天黑下来时，你的身体就知道该睡觉了。 你可以做这些事来帮自己睡个好觉。

Emotions Emotions are what we feel when we see, do, or hear about something, and they are controlled by the brain. It is normal to feel a lot of different emotions in different situations. Fear, joy, sadness, and anger are all emotions. Happy When something good happens or we do something we enjoy, it makes us feel happy. Sad We might feel sad about big changes, such as if a good friend moves away to another city. Angry We may feel angry if someone is unkind to us or if we think something is unfair. Staying healthy Everyone feels different emotions at times, and there are many things you can do to keep your mind healthy. Poor mental health can have a negative effect on your physical health, too. Writing down how you are feeling can be a great help. Mental health As well as looking after your body, it is important to take care of your mind and how you feel. This is called mental health. The state of your mental health affects how you think, feel, and act. Scared We often feel frightened if we think something bad is about to happen. People get scared by different things. Excited Looking forward to something, such as a party or a vacation, can make us feel excited. Worried It is common to feel worried when there is a problem we don't know how to handle. Talking Sharing your worries with someone else may help you feel better. It also means they can try to support you. Friends Spending time with your friends and doing activities together can make you feel happy. Sleeping If you don't get enough sleep each night, you might become irritable and find it hard to concentrate. Hobbies Doing things you enjoy helps you relax. Hobbies include painting, music, playing sports, and reading. Exercise Daily exercise, such as walking, bike riding, and swimming, keeps your mind and body healthy. Healthy eating Certain foods, like sugar, can affect how you think, so you should eat a balanced diet with a lot of fruit and vegetables.

情绪 情绪是我们看到、经历或听到一件事时产生的感受，由大脑控制。 在不同场景感受到各种各样的情绪，是一件很正常的事。 恐惧、喜悦、悲伤和愤怒都是情绪。 开心 当好事发生，或是我们做了喜欢的事，就会感到开心。 难过 遇到重大变化时我们可能会难过，比如好朋友搬到别的城市生活。 愤怒 如果有人对我们不友善，或是我们觉得事情不公平，就可能会生气。 保持健康 每个人都会时不时产生不同的情绪，有很多方法可以帮你保持心理健康。 不好的心理健康也会对你的身体健康产生负面影响。 把你的感受写下来，会很有帮助。 心理健康 除了照顾好身体，照顾好你的大脑和感受也很重要。 这就叫做心理健康。 心理健康的状态会影响你思考、感受和行动的方式。 害怕 当我们觉得坏事快要发生时，我们常常会感到害怕。 不同的人会对不同的事物感到害怕。 兴奋 期待一件事的时候，比如派对或是假期，会让我们感到兴奋。 担忧 当我们遇到不知道怎么解决的问题时，感到担忧很正常。 倾诉 和别人分享你的烦恼，会让你感觉好一些。 这也能让他们来试着支持你。 朋友 和朋友相处、一起做活动，会让你感到开心。 睡眠 如果每晚睡眠不足，你可能会变得暴躁，也很难集中注意力。 爱好 做你喜欢的事能帮你放松。 爱好包括画画、音乐、运动和阅读。 运动 日常运动，比如走路、骑车和游泳，能让你的身心都保持健康。 健康饮食 有些食物，比如糖，会影响你的思维，所以你要吃均衡的饮食，多吃水果和蔬菜。

Body talk The way you stand, what expressions you make, and how you position your hands tell others about what you're thinking and feeling, without you having to say a word! Disgust Wrinkling your nose can show you are digusted. Closed Crossing your arms in front of your chest shows you might be feeling angry. Hand gestures People often use their hands as a way of communicating. Making various shapes with your fingers and thumbs can mean certain things. Be careful though—some signs mean different things in different societies. Showing love Many people around the world make a hand gesture in the shape of a heart to represent love. Shaking hands can be a friendly way to say hello to someone. A lot of body language happens unconsciously. Facial expressions Looking at someone's face can give you a lot of information about what they are feeling. Lifting the eyebrows, smiling, or frowning communicates different emotions. Surprise Raising your eyebrows can show you are surprised. Open Opening your arms can be welcoming, or can show you feel strongly about something. Body language Body language is how the position of your body displays your feelings to others. The way you use and move your body can show someone that you are happy, sad, angry, or afraid, even if you don't tell them. Slow down! UNDERWATER SIGNS Divers exploring the ocean make signs with their hands to communicate with each other. It's impossible for them to speak since they have a tube in their mouth to help them breathe. This diver is signaling that there is a shark approaching.

身体悄悄话 你站立的姿势、脸上的表情、双手的摆法，不用开口说一个字，就能告诉别人你在想什么、感受如何！ 厌恶 皱起鼻子就说明你感到厌恶。 封闭 把手臂交叉抱在胸前，说明你可能正在生气。 手势 人们经常用手来交流。 用手指和大拇指比出不同的形状，可以表达特定的含义。 不过要注意哦——有些手势在不同地区意思不一样。 表达爱意 世界上很多人都会用手比出心形来代表爱。 握手是跟人打招呼的友好方式。 很多肢体语言都是无意识做出的。 面部表情 看一个人的脸，就能得到很多关于他感受的信息。 抬眉毛、微笑、皱眉，都能表达不同的情绪。 惊讶 抬起眉毛说明你感到惊讶。 开放 张开双臂可以表示欢迎，也能说明你对某件事感受很强烈。 肢体语言 肢体语言就是用你的身体姿势向别人展现你的感受。 就算你不说出来，你摆放、移动身体的方式也能告诉别人你是开心、难过、愤怒还是害怕。 慢一点！ 水下信号 探索海洋的潜水员会用手打手势来互相交流。 他们没法说话，因为嘴里含着帮他们呼吸的通气管。 这位潜水员正在发信号，表示有鲨鱼正在靠近。

Viruses and bacteria Viruses and bacteria are tiny organisms that can make us sick. Each bacterium is made up of one cell and can live in or on the body. Viruses are much smaller and need to get inside the body's cells to be able to survive. Viruses A virus has proteins on its surface, which allow it to infect a body cell. Once inside, the virus injects its genetic material and takes over the cell. The cell makes many copies of the virus—these are then released to infect other cells. Hand washing removes bacteria and viruses from your hands! Catching a cold Many viruses can only survive for a short time outside the body. They need to hop between people as quickly as possible to spread. Here's how a cold travels around! Bacteria Bacteria can be good or bad. Many good bacteria live in the body, for example in the intestines, and help to keep it healthy. Bad bacteria, however, can cause infections and may need to be treated with medicine called antibiotics. A person infected with a cold virus coughs on their hand. They shake hands with a friend and pass on the virus. When their friend itches their nose, the virus enters their nostrils. Now infected, the friend transfers the virus onto a handrail. Someone else touches the handrail and the virus sticks to their hand. When this person eats an apple, the virus gets in their mouth and infects them, too! VACCINES A vaccine is an injection that trains the body to kill a virus. Edward Jenner, an English doctor, invented the first vaccine in 1796. It stopped people from catching a deadly virus called smallpox.

病毒和细菌 病毒和细菌是能让我们生病的微小生物。 每个细菌都由单个细胞构成，可以在人体内外生存。 病毒要小得多，而且需要进入人体细胞才能存活。 病毒 病毒表面带有蛋白质，能帮助它感染人体细胞。 进入细胞后，病毒就会注入自身的遗传物质，接管这个细胞。 宿主细胞会复制出很多新病毒，新病毒释放后会继续感染其他细胞。 洗手可以把细菌和病毒从你的手上清除掉！ 感冒 许多病毒只能在人体外存活很短的时间。 它们需要尽快在人与人之间转移，才能传播开。 一起来看看感冒是怎么传播的吧！ 细菌 细菌有好也有坏。 很多有益细菌生活在我们体内，比如肠道里的细菌，能帮助维持身体健康。 不过有害细菌会引发感染，需要用叫做抗生素的药物来治疗。 感染了感冒病毒的人咳嗽后，病毒留在了他的手上。 他和朋友握手，把病毒传给了对方。 朋友揉鼻子的时候，病毒就进入了他的鼻腔。 被感染后，这个朋友又把病毒留在了扶手上。 另一个人摸到扶手，病毒就粘在了他的手上。 这个人吃苹果的时候，病毒进入了他的嘴里，也被感染啦！ 疫苗 疫苗是一种注射针剂，能训练身体杀灭病毒。 英国医生爱德华·詹纳在1796年发明了第一支疫苗。 它能让人们避免感染一种叫做天花的致命病毒。

Body defenses Bacteria and viruses, called pathogens or germs, can invade the body to multiply and cause diseases. The body's immune system has many defenses, which it uses to tackle the germs. Now's our chance! Germ invasion The skin acts as an excellent barrier against infection. However, sometimes scrapes and cuts happen, which open the skin's surface. It is important to keep cuts clean, since this is when germs invade. White blood cells called phagocytes surround invading pathogens and eat them. Other defenses Your immune system is constantly protecting you from pathogens. However, there are other defenses in the body that also help protect against germs. Hair Hair acts as a barrier, which some pathogens have difficulty getting past. Tears Tears contain antibacterial substances, which kill germs that get into your eyes. Saliva It's easy to eat bacteria, but saliva contains chemicals to stop them from multiplying. Mucus Slimy mucus can trap pathogens, so they can't invade the body further. Some white blood cells patrol the body to determine if cells are the body's own or not. If not, they release chemicals to kill them. Lymphocytes are white blood cells that release antibodies. These stick to pathogens and let the phagocytes know to destroy the germs. ALLERGIES The body sometimes reacts to common substances, such as dust or pollen, as if they were pathogens. This causes an allergic reaction. Allergies are usually mild, but sometimes they can be more serious.

身体防线 细菌和病毒也叫病原体或者病菌，它们会入侵人体繁殖，引发疾病。 人体的免疫系统有多种防御机制，用来对抗病菌。 机会来了！ 病菌入侵 皮肤是阻挡感染的绝佳屏障。 不过，皮肤有时候会被擦伤、割破，露出开放性伤口。 保持伤口清洁非常重要，因为病菌就是趁这个时候入侵的。 叫做吞噬细胞的白细胞会包围入侵的病原体，把它们吃掉。 其他防御机制 你的免疫系统一直在保护你远离病原体。 不过，人体内还有其他防御机制，帮助我们抵御病菌。 毛发 毛发是一道屏障，很多病原体都很难穿过它。 泪水 泪水中含有抗菌物质，能杀死进入眼睛的病菌。 唾液 我们吃东西时很容易吃进细菌，但唾液中的化学物质能阻止细菌繁殖。 黏液 黏滑的黏液能困住病原体，不让它们进一步入侵人体。 一些白细胞会在体内巡逻，判断细胞是人体自身的还是外来的。 如果是外来细胞，它们就会释放化学物质杀死它。 淋巴细胞是一种能释放抗体的白细胞。 抗体会粘在病原体上，通知吞噬细胞消灭这些病菌。 过敏 有时候人体会把灰尘、花粉这类常见物质错当成病原体，产生反应。 这就会引发过敏反应。 过敏通常比较轻微，但有时候也可能会更严重。