题目设置中桩时,在直线段,平原不大于50m,山岭不大于();A. 50mB. 30mC. 25mD. 20m设置中桩时,在直线段,平原不大于50m,山岭不大于();A. 50mB. 30mC. 25mD. 20m题目解答答案D. 20m