英国学生科学读本 第93期:蝌蚪与青蛙(1)(在线收听

   Lesson 93 Tadpole And Frog 第93课 蝌蚪与青蛙

  Children who are fond of country walks, and who use their eyes well,  喜欢在乡村漫步并且善于观察的孩子们
  will be sure to notice in early spring little lumps of jelly floating on some pond by the roadside. 一定在早春时分看到过这样的场景:路边的池塘中经常会漂浮着一小块一小块的胶状物体。
  This jelly-like stuff consists of a number of frogs' eggs or "spawn. " 这些胶状物质由大量的青蛙卵, 叫做“卵块”组成。
  If we look at the spawn very closely, we shall see a great many black specks. 仔细观察, 就会发现这中间有很多黑色斑点,
  Each of these specks is the centre of an egg. 每一个斑点就是青蛙卵的核心部分。
  Let us return to the pond a month later. 一个月之后再回到池塘,
  The spawn has gone, for all the eggs have burst open, and out of each one has come a little animal called a tadpole. 这些卵已经不见了, 因为它们全部破裂开来, 从中钻出了一种名叫蝌蚪的小动物。
  Tadpoles are very funny-looking little things about an inch in length, each with a large round black head and a flat tail. 蝌蚪的样子非常有趣:体长一英寸左右, 脑袋又大又圆, 尾巴却是侧偏的。
  They swim about in the water by the help of their tail, and they are very much like little fishes in many other ways.  它们通过摆动尾巴在水中游走, 除此之外, 它们和鱼还有很多类似之处。
  They have little pink gills, which stick out on each side of their head. 蝌蚪脑袋的两侧分别长有一个粉红色的小鳃。
  By its gills the tadpole can breathe the air which is dissolved in the water, just as a fish does. 通过这个器官, 蝌蚪便能够像鱼那样呼吸溶于水中的空气。
  The little creature soon dies if it is taken out of the water, for it cannot breathe the air as we do. 它们离开了水, 很快就会死去, 因为它们无法和人类一样呼吸空气。
  Each tadpole has a mouth with tiny teeth to gnaw the plants on which it feeds.  每只蝌蚪的嘴巴里都长有细小的牙齿, 用来刮食植物。
  It is very curious to watch the changes that take place in the tadpole during the three months or so that it lives in the water. 蝌蚪在水中生活三个月的时间, 这期间, 它们的身体能够发生很多有趣的变化。
  The gills become covered over, and lungs grow inside the body to do their work. 鳃逐渐被覆盖起来, 身体内部长出了肺, 用于进行呼吸。
  The tail becomes shorter, and near it two legs break through the skin. 蝌蚪的尾巴变得更短, 而旁边则长出两条小腿。
  Then other two legs come out nearer to the head. 很快, 头部附近也会出现这样的两条腿。
  原文地址:http://www.tingroom.com/lesson/syysdw/mgxskxdb/447736.html