釉质中的有机质多分布在以下结构中，除了（）
A.釉板
B.釉丛
C.釉梭
D.釉柱间质
E.釉牙本质界
参考答案：E
正常男性体细胞中性染色体的组成用______表示．
—Where _____ Mary have put the empty bottles?
— She _____ them away. They must be somewhere.
A．can; can’t have thrown
B．must; needn’t
C．must; must have thrown
D．can; mustn’t have thrown
