附着升降脚手架的架体外侧可以不用密目安全网围挡。（）
参考答案：错
10BaseT is an Ethernet LAN term meaning a maximum transfer rate of 10Mbps that uses baseband signaling and twisted pair cabling. A 10BaseT Ethernet LAN has a ______ topology.
A．star
B．ring
C．bus
D．none of the above
B细胞识别抗原的受体是（）
A.SRBC受体
B.Fc受体
C.C3b受体
D.SmIg
E.TCR
