第一级: first order; first step; fir ...卡: wedge; get stuck; be jammed圈: circle; ring第一级: first order; first step; first stage卡圈: circlip; clamp; collar; rand; retainer ring第一级光谱，第一级谱: first order spectrum第一级侧脉: lateral vein of the first order第一级产业: primary sector of economic activity第一级次: first order第一级导叶: first stage guide vane第一级的: primary第一级地址: first level address第一级反射: first order reflection第一级飞行: first-stage flight第一级股市: mainboard第一级光谱: primary spectrum; spectrum of first order第一级焊接: first class welding第一级活动: primary activity; primaryactivity第一级记忆: primary memory第一级检验: first order tests第一级美棉: midding fair第一级配位: first coordination第一级平台: kelly platform第一级亲属: primary relatives第一级燃烧: stage-one burning
