2 Food Chains and Food Webs-Mid

Food Chains and Food Webs Written by Kira Freed

食物链和食物网作者:基拉·弗里德

Introduction Ana sits down at the table for a breakfast of oatmeal, yogurt, and orange juice before going to school. The food she takes in will provide energy for learning, gym, and her other morning activities. Where did the energy in her food come from? This book explores how living things get the energy and matter they need to survive. You will learn how one living thing depends on another and that all living things depend on energy from the Sun. You will also learn what happens when a food source is taken away.

安娜在上学前坐下来吃早餐，吃燕麦片、酸奶和橙汁。 她摄入的食物将为她的学习、健身和其他上午活动提供能量。 她食物中的能量从何而来? 这本书探讨了生物如何获得生存所需的能量和物质。 你将了解一个生物如何依赖另一个生物，所有生物都依赖太阳的能量。 你还将了解当食物来源被拿走时会发生什么。

Producers and Consumers Living things are either producers or consumers. Producers produce, or make, their own food. Green plants are the main producers. They produce food by using energy from the Sun to combine water with a gas from the air. This process is photosynthesis. Without the Sun's energy and the producers that use it for photosynthesis, most living things on Earth would not survive. Consumers cannot make their own food. Instead, they depend on producers for food. For example, grass is a producer. When a cow eats grass, the cow is a consumer. Consumers eat, or consume, producers or other consumers. The cow that munched on the grass was growing and also making milk. When you drink a glass of milk or eat a hamburger, you are a consumer, too. Producers and consumers depend on each other in many ways. Let's learn about their relationships.

有生命的东西要么是生产者，要么是消费者。 生产者自己生产食物。 绿色植物是主要的生产者。 它们利用来自太阳的能量将水和空气中的气体结合起来生产食物。 这个过程就是光合作用。 如果没有太阳的能量和利用它进行光合作用的生产者，地球上的大多数生物将无法生存。 消费者不能自己做食物。 相反，他们依靠生产者提供食物。 例如，草是生产者。 当牛吃草时，它就是一个消费者。 消费者吃，或消费，生产者或其他消费者。 吃草的那头牛在生长，也在产奶。 当你喝一杯牛奶或吃一个汉堡时，你也是一个消费者。 生产者和消费者在许多方面相互依赖。 让我们来了解一下他们的关系。

Food Chains Food chains show how one living thing depends on another living thing for food and how energy and matter move from producers to consumers. Since producers make food, they are the first link in a food chain. A food chain has only one link for producers but many links for consumers. Primary consumers are living things that eat plants. They are the next link in a food chain. Grasshoppers and elephants are both primary consumers, or herbivores. They only eat producers (plants).

食物链展示了一种生物如何依赖另一种生物来获取食物，以及能量和物质如何从生产者转移到消费者。 由于生产者生产食物，他们是食物链的第一个环节。 食物链对生产者来说只有一个环节，但对消费者来说有很多环节。 主要消费者是吃植物的生物。 它们是食物链的下一环。 蚱蜢和大象都是主要的消费者，或食草动物。 它们只吃植物。

Herbivores often have special body parts that help them get and use the energy stored in certain plant parts. For example, parrots have tough beaks that can crack open the hard outer cases of tropical fruits and nuts. Elephants have special teeth to grind bark. Even with special body parts, many herbivores must spend a long time eating to obtain enough energy to stay alive.

食草动物通常有特殊的身体部位，帮助他们获取和利用某些植物部位储存的能量。 例如，鹦鹉有坚硬的喙，可以打开热带水果和坚果坚硬的外壳。 大象有特殊的牙齿来磨树皮。 即使有特殊的身体部位，许多食草动物也必须花很长时间进食才能获得足够的能量来维持生命。

To review, the first link in a food chain is the producers, or plants. The second link is primary consumers, or herbivores. The third link is secondary consumers— animals that eat the herbivores. These animals are carnivores, or meat eaters. When people think of carnivores, they often think of animals such as tigers and wolves. But other animals, such as insect-eating spiders, anteaters, and some bats, are also carnivores. So are penguins, bald eagles, and other fish eaters. Can you guess the next link in a food chain? After primary consumers (which eat plants) and secondary consumers (which eat herbivores), many food chains have tertiary consumers— carnivores that eat other carnivores. For example, let's say a mouse (primary consumer/herbivore) eats grass, and a snake (secondary consumer/ carnivore) eats the mouse. A hawk that eats the snake is a tertiary consumer.

回顾一下，食物链中的第一个环节是生产者，或植物。 第二个环节是主要消费者，也就是食草动物。 第三个环节是次要消费者——以食草动物为食的动物。 这些动物是食肉动物。 当人们想到食肉动物时，他们通常会想到像老虎和狼这样的动物。 但其他动物，如食虫蜘蛛、食蚁兽和一些蝙蝠，也是食肉动物。 企鹅、秃鹰和其他吃鱼的动物也是如此。 你能猜到食物链的下一个环节是什么吗? 在主要消费者(吃植物)和次要消费者(吃食草动物)之后，许多食物链还有第三消费者——吃其他食肉动物的食肉动物。 例如，假设一只老鼠(主要消费者/食草动物)吃草，而一条蛇(次要消费者/食肉动物)吃老鼠。 吃了蛇的鹰是第三消费者。