The Company switches are configured to use VTP. What’s true about the VLAN trunking protocol （VTP）？（） ["VTP messages will not be forwarded over nontrunk links.","VTP domain names need to be identical. However，case doesn’t matter.","A VTP enabled device which receives multiple advertisements will ignore advertisements with higher configuration revision numbers.","A device in "transparent" VTP v.1 mode will not forward VTP messages.","VTP pruning allows switches to prune VLANs that do not have any active ports associated with them."]
“三致”作用
旅游专列是指由（）要求临时开行并往返全部包用的旅客列车。 ["旅行社或单位","旅游局","旅行社","铁路运输企业"]
先列选项中对“小腿或脚趾抽筋时”的应急处理叙述正确的是（） ["用抽筋小腿对侧的手握住抽筋腿的脚趾，用力向上拉伸，同时用同侧的手掌压在抽筋小腿的膝盖上，帮助小腿伸直","弯曲大腿与身体成直角，并弯曲膝关节，然后用两手抱着小腿，做震荡动作，随即向前伸直，如此反复进行","抽筋者躺在平地上，另一人抓住抽筋小腿做前后的伸直和弯曲，并如此反复进行","抽筋者躺在平地上，另一人用脚对抽筋小腿做反复的踢踏"]
经过多代选择的育成品种（纯系品种），其优质的生产性能是以高度杂合的遗传基础为基础的。
觉察
