低于: to be lower than...
重叠: to overlap, to superimpose, to telescope, to run together, to duplicate, one over another, superposition, an overlap, redundancy, reduplication (in Chinese grammar, e.g. to have a stroll)...
滑: to slip, to slide, smooth, slippery, cunning...
留神: to take care, to be careful...
地板: floor...
畅通: unimpeded, free-flowing, straight path, unclogged, move without obstruction...
