zì rú
freedom of action
unobstructed
unconstrained
smoothly
with ease
freely
yùn yòng zì rú
to operate easily (idiom); to use freely
to have fluent command of
to have sth at one's fingertips
yìng fu zì rú
to handle matters with ease (idiom); equal to the situation
jìn tuì zì rú
free to advance or retreat
room for maneuver
cāo zòng zì rú
ease of operation
to control smoothly