Slithery Snakes

Slytheri Snakes. Written by Ned Jensen. Focus question. What are snakes?

《滑溜溜的蛇》 作者：内德·詹森 核心问题：蛇是什么？

Introduction Snakes are reptiles. There are several thousand kinds of snakes. They live in oceans, in trees, and on land, and they survive in unusual ways.

引言 蛇属于爬行动物，世界上有数千种不同的蛇。 它们栖息在海洋、树上和陆地上，有着非同寻常的生存方式。

Wild snakes live almost everywhere on Earth, except Antarctica and some islands. Some wild snakes may live as long as 25 years.

除了南极洲和部分岛屿之外，野生蛇几乎遍布地球的每个角落。 部分野生蛇的寿命最长可达25年。

Snake traits. Snakes are cold -blooded. Their body temperature changes with the temperature around them. Snakes find sunshine to stay warm. They find shade to stay cool. During winter, some snakes stay underground or under rock piles to stay warm. Snakes also rest in groups to share body heat.

蛇的特征 蛇是冷血动物。 它们的体温会随着周围环境的温度变化而变化。 蛇会晒太阳来保持体温。 它们会躲到阴凉处降温。 冬天的时候，有些蛇会待在地下或者石堆下面保暖。 蛇也会成群休息，互相分享体温。

Snakes have long backbones. Their backbones have many separate bones, which lets them move in many ways. A snake's body is covered in scales. The scales protect it. They also help keep the snake dry. The scales grow from its skin. Snakes use their scales and muscles to move. The scales on their belly grab the surface beneath them. Their muscles help them move along the ground. Some even use their muscles and scales to climb trees.

蛇有长长的脊椎。 它们的脊椎由很多块独立的骨头组成，这让它们可以灵活地向各个方向活动。 蛇的身体覆盖着鳞片。 鳞片可以保护蛇的身体。 还能帮助蛇保持身体干燥。 鳞片是从蛇的皮肤里长出来的。 蛇靠鳞片和肌肉移动。 它们腹部的鳞片可以抓住身下的接触面。 肌肉则推动它们在地面上行进。 有些蛇甚至还能靠肌肉和鳞片的配合爬上树。

Snake scales look like a single sheet of skin. Snakes don't shed skin. Instead, they shed the outer layers of their scales up to four times per year. This is called molting. When molting, snakes rub against something like a rock or log. This helps their outer layer stretch and split. Young snakes shed more because they grow fast. Snakes also shed to get rid of pests on their scales.

蛇的鳞片看起来就像一整块皮肤 但蛇并不会整张蜕皮 相反，它们每年最多会蜕四次鳞片外层 这个过程叫做蜕皮 蜕皮的时候，蛇会在岩石或者圆木这类东西上摩擦 这能帮助外层鳞片撑裂开 幼蛇长得快，所以蜕皮的次数更多 蛇蜕皮也是为了去掉鳞片上附着的寄生虫