VHF发射机的调制度应当大于() ["75%","80%","85%","90%"]
碳素结构钢抗拉强度的修约间隔为()。 ["0.1MPa","1MPa","5MPa","10MPa"]
射流离心选矿机是()分选设备。 ["中细粒","超细矿泥","细粒物料","中粒度物料"]
VHF发射机寄生频偏应小于()Hz。 ["5000","1000","1500","2000"]
等距抽样是指() ["简单随机抽样","系统抽样","分层抽样","多阶段整群抽样"]
简述陕飞从耕战论到“农本工商末”口号的提出。