To move up or down the ladder, step by step by step. Don't move at three floors will cause they failed. Like that will do anything to gradually. Don't do anything that exceeds the ability or skip steps.
To step up or down stairs The step-by-step by step. never ever step three floors Make a livelihood without success. , like how to do anything. The gradual giving up the ability to do nothing. Or skip steps
To step up or down the stairs, step by step by step don't step three is done quite tricky failed. like no matter what you do, don't do anything to gradual beyond or ข้ามขั้นตอน.