bubble-up loop circulation

air bubble growing up

bubble coalescence and break-up

bubble hole-up

pick-up up hay baler

Bubble and Bubble BnB

bubble cap absorption column; bubble cap absorption tower

Gas bubble growth-gas bubble detachment

boot-up speeding up

half built up crank shaft [= semi-built-up crank shaft

Hold Up And Stop Up Rotating

on the up-and-up

put up or shut up

sequence of train breaking up and making up

up-and-up

up-supply and up-discharge

up-supply and up-exhaust

WARM UP; WARMING UP

[magnetic] half-bubble