double-shell

英['dʌblʃ'el] 美['dʌblʃ'el]
  • n.双壳
  • double adj.双重的;成双的;两倍的v.翻一番;使...加倍n.两倍;双份
  • j n.字母j
  • tubes n.管子;管状物;地铁;电视;管状器官v.提供或装上管子
    用作名词 (n.)
    1. There is a case of an oysterlike bivalve that evolved a more and more spiraled shell until, just before extinction, the valves could barely open.
      这里有个例子,一种牡蛎状双壳类,进化出越来越趋螺旋状的外壳,直到该物种灭绝,其外壳已几乎不能打开。