正常淋巴结结构如图，请分别指出图中所示结构名称。
D为（）
A.皮质区
B.生发中心
C.髓质区
D.副皮质区
E.套区
参考答案：B
试述银屑病的病因和发病机制。
He failed to carry out some of the provisions of the contract, and now he has to () the consequences.
A. answer for
B. run into
C. abide by
D. step into
