Mike has much difficulty ________ Chinese so he often asks me ________ help.

A．to understand, with

B．understanding, of

C．to understand, for

D．understanding, for

关于斑块哪一项是错误的（）

A.局限性隆起的皮疹

B.皮疹的直径大于1cm

C.斑块多由丘疹融合而成

D.斑块可由斑片扩大而成

E.斑块常见于银屑病