placode中文什么意思

例句与用法

1. Feather growth begins with a thickening of the epidermis called the placode , which elongates into a tube ? the feather germ [ see illustration above ]
   首先，表皮上的基板开始增厚，并拉长成一根管子，称为羽芽（见上方羽毛的成长过程） 。