（）不会直接造成定位表面接触不良。A、定位元件与工件之间的定位处于强制状态 B、定位点

维生素B缺乏可引起（）

A.口角炎、唇炎

B.舌炎

C.甲状腺功能减退

D.脂溢性皮炎

E.眼痛、流泪、畏光

For each blank, choose the best answer from the four choices and write down on the answer sheet.
(21) is a six bytes OSI layer 2 address which is burned into every networking
device that provides its unique identity for point to point communication.
(22) is a professional organization of individuals in multiple professions which focuses on effort on lower-layer protocols.
(23) functions with two layers of protocols. It can connect networks of different speeds and can be adapted to an environment as it expands.
(24) is the popular LAN developed under the direction of the IEEE802.5.
(25) is the popular backbone technology for transmitting information at high speed with a high level of fault tolerance which is developed under the direction of ANSI.

A．Ethernet

B．Token Bus

C．Token Ring

D．DQDB

继发性癫痫是（）

A.继发于脑部的器质性病变

B.高热以后发生的痫性发作

C.一种以上发作类型的癫痫

D.成年以后的癫痫发作

E.药物治疗疗效差

房地产相邻权

众所周知，IgE参加（）。

A.吞噬细胞反应

B.被动免疫反应

C.变态反应

D.网状内皮系统的反应