题目内容
(请给出正确答案)
[主观题]
What role does nacre play in the formation of pearls?A.It provides the nucleus around whic
What role does nacre play in the formation of pearls?
A.It provides the nucleus around which a natural pearl develops.
B.It is a calcium coating that protects the outside of the oyster's shell.
C.It penetrates the membrane covering the oyster's soft body.
D.It is the luminous substance that forms the pearl's outer layers.
如搜索结果不匹配,请 联系老师 获取答案