从差的着陆进近情况下复飞应该() ["开始拉平后不尝试,不管空速","不尝试,除非环境需要","通常在最后时刻尝试,防止做差的着陆"]
()是实现领导职能的根本途径 ["领导方法","领导手段","领导原则","领导方针"]
在资本主义社会里,雇佣工人新创造的价值是() ["v+m","c+v","c+m","c+v+m"]
紧急情况全襟翼复飞时,飞机难于操纵的原因是() ["大功率低速时,全襟翼形态下,飞机未配平","全襟翼,空速过大","迎角减小,全襟翼状态下飞机操纵性降低"]
定量预测的方法() ["平均值法","指数平滑法","回归分析法","能力基础预测法"]
按照国际隧道协会(I√A)定义的隧道的横断面积的大小划分标准分类,隧道可分哪几类及其划分标准是多少?