为了减少切削力对钻削振动的影响，先预钻底孔，再扩孔精钻，扩孔余量为（）mm左右。 ["0.25～0.5","0.5～1","1～1.5","1.5～2"]
临修时，装用转8A型转向架的车辆在重车时的车钩高度≤（），且均不低于815mm。 ["860mm","855mm","865mm","870mm"]
包装从材料上可以分为（） ["金属","玻璃","袋","盆"]
以冲裁模为例，大多数（）便于机械加工，淬火后也便于研磨。 ["凸模","凹模","固定板","卸料板"]
著名诗人刘克庄是（） ["江西诗派传人","元祐诗派巨擘","江湖诗派宗师","遗民作家先驱"]
外来流体对油气层的伤害有哪些特点？
