Crossword puzzle clue "word with level or legs"

"I go on four legs in the morning, on two legs in the afternoon, and on three legs in the evening ..."

Source of the maxim "Four legs good, two legs bad"

Low-level pollution or high-level protection

Warning sign at a train station's food court? (NOTE: The original sign, without my additions, actually exists. It's in Grand Central Terminal in NYC, on the lower level — the food court level. The sig

Class, level or class level

Management level or theater level