介于: between, intermediate, to lie between...
逐步: progressively, step by step...
更: more, even more, further, still, still more...
棍子: stick, rod...
狠: ruthless, fierce, ferocious, determined, to harden (one's heart), old variant of...
薪水: salary, wage...
憋: to choke, to stifle, to restrain, to hold back, to hold in (urine), to hold (one's breath)...
限定: to restrict to, to limit...
门口: doorway, gate...
进步: progress, improvement, to improve, to progress...