無動于衷aloof;indifferent;unconcerned
無價之寶an object that is priceless or an asset (can also refer to abstract things)
無精打采dispirited and downcast;listless;in low spirits;washed out
無可奉告“no comment”
無可奈何have no way out;have no alternative
無理取鬧to make trouble without reason;deliberately awkward;pointless provocation;willful trouble maker
物美價廉cheap and fine;attractive in price and quality
無能為力impotent;powerless;helpless
無窮無盡vast and limitless;endless span of time;no vestige of a beginning;no prospect of an end
無微不至in every possible way;meticulous