double-shell

英 ['dʌblʃ'el] 美 ['dʌblʃ'el]

• n. 双壳

例句

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。