鱼塘里生活着一种奇怪的动物,它身体又扁又长,从头到尾只有0.2至0.8毫米,用肉眼只能勉强看见它的外形,至于要看清楚它的内部构造,那就非用显微镜不可了。但是,这种比芝麻还小十倍的动物,它“怀孕”的本事却大得恨,身体里怀有第一胎(第一胚胎)后,接着就在这个胚胎里“怀孕”着第二胎(第二胚胎)。这样,就“三代同身” There is a weird animal living in the fish pond. It is flat and long, with a length of 0.2 to 0.8 millimeter. It can barely see its appearance with the naked eye. To see clearly its internal structure, Microscope inevitable. However, this animal, which is 10 times smaller than sesame seeds, is greatly hated for its ability to “become pregnant,” after having the first embryo (the first embryo) in the body and then “pregnant” the second in this embryo Tire (second embryo). In this way, on the “three generations of the same body”