to take over (from those working the previous shift), to take over (in a leadership role etc), to succeed sb

flight of steps, (fig.) a means of advancement, stepping stone

one after another (idiom), in quick succession

都, 都是（常用于书面语）

to give material assistance to

state, social class, degree, people, gradation, echelon, persuasion, position, order, class, remove, social status, notch, parity, social rank, sort, step, condition, rank, social station