"When is ____ birthday?" "Her birthday is October fifth."[ ]

A. your brother's  

B. Jack sister  

C. his sister's  

D. Lucy's brother's

朗格汉斯细胞的结构特点有（）

A.光镜下细胞呈多角形，胞质透明

B.胞核较小并呈分叶状，线粒体、高尔基复合体、内质网丰富，并有溶酶体

C.电镜下细胞核呈扭曲状，无张力细丝、桥粒和黑素小体，胞质清亮

D.内有特征性的Birbeck颗粒