点缺陷
Spanning Tree Protocol IEEE 802.1s defines the ability to deploy which of these？（） [" one global STP instance for all VLANs"," one STP instance for each VLAN"," one STP instance per set of VLANs"," one STP instance per set of bridge"]
接触角
固溶体的晶格类型与组元的晶格类型是（）。 ["相同","不同"]
《铁路旅客运输规程》行李、包裹的运到期限，从承运日起，行李600千米以内为（）日 ["一","二","三","四"]
重介质选矿
