fixed ventilation tunnel
tunnel ventilation in construction
underground ventilation tunnel
Transit tunnel of subway
gate lintel ventilation plus ventilation behind ga
synchronized intermittent mandatory ventilation plus pressure support ventilation
diversion tunnel and spillway tunnel
option of separate highway tunnel and Metro tunnel
railway tunnel under crossing the highway tunnel
Shield Tunnel and Rock Tunnel
water tunnel and salt tunnel
(superscript 133)Xe ventilation scintigraphy
99mTc DTPA aerosol ventilation scintigraphy
accommodation ventilation