往返双程光信号  To-and-fro two way light signal

20米往返跑  20-meter shuttle run test

被遣返往内地  be sent back across the border

穿梭往返  shuttle

垂直往返式冷凝器  vertical reciprocating condenser

电波往返行程  hop

定期往返于  ply between

反射波往返时  round travelling time of reflection wave

金属丝往返试验机  wire repeated tester

平滑往返时间偏差  delta

平均往返时延  average RTT

平面往返折迭  plate fold

市郊往返列车  commuter train

天地往返运载器  launch vehicle

往返测法  to-and-fro method

往返潮流  reversing tidal current

往返程时滞  Round-trip time delay

往返程租赁  round trip leasement

往返冲程计数器  stroke counter