Answer: metros

AnswerCrossword Clue
METROS

Major-city areas

METROS

Subway systems

METROS

Some undergrounds

METROS
Little cities?
METROS
Underground complexes
METROSTransit systems in Delhi and Paris
METROSTwo world capital transits
METROSSome Geos
METROSSubterranean railways
METROSUndergrounds
METROSCity subways
METROSSome transit lines
METROSDC and Paris railways
METROSSubways
METROSMoscow and Paris subways.
METROSUndergrounds.
METROSSubways, in Europe.
METROSParis subways
METROSParis subway lines
METROSParisian lines
METROSEuropean subways
METROSSubways in Milan, Paris, etc.
METROSSubways on the Continent
METROSUnderground systems
METROSUrban railways
METROSSome urban transit systems
METROSUnderground railways of Paris and D.C.
METROSSome public-transit systems, briefly
METROSWashington and Paris transit systems
METROSParis tubes
METROSPublic transportation
METROSUnderground transport systems
METROSGeo models
METROSWashington and Paris transits
METROSTwo capital transits
METROSSome transit systems
METROSSome have red lines
METROSSmall Chevys
METROSUnderground networks