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一.主要科学内容本章是继鱼纲之后,通过青蛙的形态构造和生殖发育过程研究两栖类的特征,并有系统地研究两栖类的起源和分类。本章共分五节,包括导言可分四个主要内容:(1) 导言主要是通过蛙为例指出两栖类的基本特征,即“幼体有鳃生活在水中;成体有肺,可以生活在水中或陆上”。以及两栖类跟人生的关系,是为全章中心科学内容。(2)包括前三节:即青蛙的形态和生
I. The main scientific content This chapter is following the fish class, through frog morphological and reproductive development of amphibian characteristics, and a systematic study of amphibian origin and classification. This chapter is divided into five sections, including the introduction can be divided into four main elements: (1) Introduction The main feature is through the frog pointed amphibians, “larvae gills living in the water; adult lung, you can live in water or Land. ” As well as the relationship between amphibians and human life, is the center of the whole chapter of the scientific content. (2) Including the first three sections: the frog’s morphology and health