儿童的一般认知能力差异集中体现在（）等方面。 ["发展水平差异","气质类型差异","表现早晚差异","结构差异"]
为防止跨步电压伤人，防直击雷接地装置距建筑物各构筑物出入口和人行道的距离不应小于（）米。 ["8","6","3","2"]
下列哪些体现了医学科研的“三严”作风（）。 [" 在坚实的业务知识和统计学知识的基础上进行试验设计"," 保证试验结果的重复性"," 因某种原因导致科研报道失误，应主动及时更正"," 客观地记录各项观察指标和试验数据"," 诱导受试对象取舍数据"]
带电检测绝缘子前应对（）进行检查。 ["电杆","拉线","检测器","金具"]
You are the network consultant from Cisco.com. Please point out which Layer 2 access designs does not support VLAN extensions?（） [" Flex Links"," loop-free U"," looped square"," looped triangle"]
简述槽模构造的特征及意义。
