перший ступінь
camshaft gear (timing gear)
gear reduction unit / gear-reduction unit
bottom
bottom mine
bottom of the hull
bottom plating
bottom sweep
double bottom
double bottom space
inner bottom
outer bottom
bottom carriage
bottom end of stroke
bottom escape
bottom gun carriage
bottom half
bottom of a bull's eye
bottom plate
bottom rib of piston
bottom run (of tank track)
bottom sleigh
bottom surface of bolt
bottom-dump hauler
bottom-of-the-barrel reserves
crankcase bottom half
hull bottom plate
alkylate bottom
bottom dead center (BDC)
bottom echo
bottom echo signal
silo-bottom launch
send to the bottom