(
课件网) Unit 5 Water is life 主题范畴： 人与自然 主题群： 环境保护 子主题： 环境污染及原因，环保意识和行为 Key question What does water mean to us Understand the importance of water in the human body; Recognize the connection between water conservation and environmental protection; Develop research and critical thinking skills through exploring water-related issues. Learning objectives 学习目标 At the end of the class, I’ll be able to: Section 4 Extending and developing competencies | Biological science Before-learning Water in the Human Body: Essential Functions Transport nutrients and oxygen Water is vital for the human body to function properly, including its role in blood circulation, metabolism, and waste removal (urine). Regulate body temperature Remove waste through urine (尿液) Protect organs and joints The function of water in urine and hydration. How does water affect our skin, muscles, and brain How does water affect our skin, muscles, and brain Water is important to life. About 55%–60% of the adult human body is water. Let’s find out more facts about water in the human body. While-learning The water in our bodies All living things need water. In fact, water is an important part of all plants and animals. For example, about 95% of the weight of a cucumber is water. For animals, that figure is usually around 60%. When we are born, about 70%–80% of our body weight is water. This number goes down as we grow up. For an adult man, water makes up about 60% of the body weight. The amount of water is a bit lower for women: around 55%. This is because women usually have more body fat than men. A lot of water leaves our bodies every day, so we need to replace it. Adults need to drink about 2–3 litres per day to stay healthy. Every time we go to the bathroom, we lose water. Every day, there is around 1.5 litres of water in our urine. If your urine is very yellow, you need to drink more water. The body also loses water to help it cool down. This is called sweat. We lose about 500 ml of water as sweat per day. It is normal to sweat a lot when we do sport or go out in hot weather. However, if we lose more than 5% of our body weight in water, we will get tired. It is dangerous to lose more than 10%. If that happens, we will feel ill. Remember to bring a water bottle every time you play sport! What is the main idea of the passage It mainly introduces the significance of water for living things and water in the human body. Read para. 1 and answer the question. All living things need water. In fact, water is an important part of all plants and animals. For example, about 95% of the weight of a cucumber is water. For animals, that figure is usually around 60%. How much of the weight of a cucumber is water About 95%. Read para. 2 and answer the question. When we are born, about 70%–80% of our body weight is water. This number goes down as we grow up. For an adult man, water makes up about 60% ... ...
