OSI is a theoretical model that shows how any two different systems can communicate with each other．Router, as a networking device, operate at the (71) layer of the OSI model．

A．transport

B．application

C．network

D．physical

患者，女，59岁，发现左眼上睑肿物5个月，渐增大。体检：左眼上睑外侧睑板见黄白色结节状肿物，实性，质地较硬韧，表面溃烂。显微镜下见：瘤细胞呈巢状排列，细胞多边形、不规则形，细胞质泡沫状，胞核较大，圆形、不规则形，异型明显，核分裂较常见。部分瘤细胞核呈空泡状。正确的诊断是（）

A.鳞状细胞癌

B.基底细胞癌

C.睑板腺癌

D.睑板腺囊肿

E.睑腺炎