450)=450"> 450)=450"> 每天18：00准时更新 全文听写，英式拼法 450)=450"> [color=#408080]HINTS NONE [/color]
In our world of living things we have plants, animals and people. Plants belong to a group called the Plant Kingdom while animals and people belong to the animal Kingdom. Look around you and you will see many different types of animals. Some animals are tiny while others are very large. Some animals are soft and long, while others are hard and rounded. Different types of animals which are alike in certain ways are put into groups. Let us find out how animals are put into groups. We can put animals into groups by studying their behaviour. We want to know how their bodies work, how they live, how they produce their young, how they find their food, what they eat, how long they live, and so on. We also have to examine the different parts of their bodies. When we examine them, here are a few questions we must ask ourselves, do they have scales, feathers or fur on their bodies? How many legs do they have? How many wings are there? Are there fins? But the first and most important question is, do the animals have backbones or not? All animals with backbones are put into one big group called vertebrates. All animals without backbones go into another group called invertebrates.
无脊椎动物是身体里边没有脊椎和其他的骨头。一些有柔软的身体和比较硬的壳来保护他们的身体。 脊椎动物是身体里边有脊椎和骨头的动物。这些骨头来帮助支撑他们的身体。脊椎动物主要有五大类，鱼类，两栖动物，爬虫动物，鸟类和哺乳类动物。鱼类，两栖动物和爬虫动物被认为是冷血类脊椎动物。热血脊椎动物不论在温暖还是寒冷的天气都保持一样的体温。 鱼类生活在水里，身上的鳞帮助它们游泳。鱼是由头，躯干和尾巴组成。尾巴以尾巴上的鳞片尾巴。鱼有很多不同的种类，不同的形状和颜色。有一些鱼很又长又瘦但有一些又平坦又圆。大多数鱼有宽大的躯干和窄小的头部和尾巴。 ——By lsy34