ultraismn.激进论；极端主义ultraadj.超；过激的；极端的n.过激论者；急进论者ultrasound placenta images胎盘超声图像ultra -front relief valve超前排气Ultra-low repetition rate超低频ultrasound aided extraction超声提取Ultrashort pulse technology超短脉冲技术ultrashort wave transmitter超短波发射机ultrasound Doppler's methodultra-low-melting alloy超低熔合金ultra-high speed sampling超高速采样ultrahigh frequency antenna特高频天线