You are about to migrate a customer network to use a VSS. Which of these statements is true about a VSS？（） ["The VSS switch must be the root bridge for all VLANs and is automatically designated.","The VSS switch is defined in RFC 4318 as a managed object.","The PAgP+ or LACP protocols are used to maintain the operational state of the VSS devices.","A VSS interoperates with a virtual port channel.","The 802.1Q or ISL protocols are used to maintain the operational state of the VSS devices.","A VSS increases the size of the spanning-tree domain."]
1850 TSS实现PTN与MSTP任意混合组网的关键技术是（）？ ["1588V2","通用交换矩阵","CES仿真","双平面矩阵"]
简述教育公共关系的特征。
串行接口芯片8251A（） ["只能异步传送","只能同步传送","可以同步或异步传送","可以同步和异步传送同时进行"]
《动车组列车服务质量规范》内容包括（）。 ["厕所内芳香盒和水溶性好的卫生纸","坐便器有一次性坐便垫圈","小便池内放置芳香球","厕所内有洗手液"]
国际货物买卖合同
