observing tube
... observerscope 二人用内窥镜 observing tube 观察管 obstetric(al) 产科的 ...
surveillance tube
... 定期测试 surveillance test 观察管 surveillance tube (一)测量(二)调查 survey ...
observation pipe
观察管
Moisture and Liquid Indicator
BH
Management Observer ; Digest of Management Science