Communities of these organisms secrete calcium carbonate, often building up concentric rings of deposits forming cushions up to a meter in diameter.

 
  • 这类生物分泌碳酸钙,常能形成一个个同中心的环状沉淀物,由此构成直径长达一米的垫样岩石。
今日热词
目录 附录 查词历史