压缩空气的设备由以下哪几部分构成()。 ["空气压缩机","油水分离器","储存罐","输气管"]
维生素D缺乏性佝偻病可靠的早期诊断指标是() ["干骺端临时钙化带消失","血清钙、磷浓度降低","血清活性维生素D水平明显降低","方颅、鸡胸或漏斗胸","多汗、夜惊、烦躁"]
桔梗祛痰的有效成分是() ["多糖","黄酮","皂苷","挥发油","生物碱"]
等螺旋角锥度刀具,如果螺旋角为常量,导程随()增大而增大。 ["π","直径","工件螺旋角","铣削时工件旋转度数"]
《秋夜》的景物描写
经济利润