使用液压直轨器时,活塞行程不宜大于(),防止发生故障。 ["A.60mm","B.65mm","C.70mm","D.75mm"]
曲线半径为800m的正线,圆曲线正矢最大最小值差,作业验收容许偏差为()。 ["3mm","6mm","9mm","12mm"]
曲线半径为700m的正线,缓和曲线的正矢与计算正矢差,作业验收容许偏差为()。 ["A.3mm","B.4mm","C.6mm","D.9mm"]
()不是造成轨道高低不平顺的主要因素。 ["A.路基沉陷","B.捣固不良","C.枕木腐朽","D.轨距变化"]
儿童理解语言迅速发展阶段的年龄段是() ["1~1岁半","1岁半~3岁","2、3岁~6、7岁","6岁以后"]
毛细血管扩张症以()序列最佳