Ключевые слова: accuracy, adjusting, background, balance, bob, build, builder, check, concept, concrete, construction, design, equilibrium, equipment, fall down, gravity, industrial, instrument, labor, level, line, measure, measurement, metal, object, old, order, outdoor, plumb, plumb bob, plumb line, plumbing, plummet, precision, red, rope, rusty, site, steel, straight, string, tool, vertical, vertically, weight, work, work tool, worker,