例句：
One has to ask oneself what the purpose of the exercise is.
大家必须问一问自己，这个锻炼的目的是什么。
It is difficult to make oneself concentrate for long periods.
让自己长时间聚精会神是很困难的。
She forced herself to keep going.
她强迫自己坚持下去。
She runs the business by herself.
她自己经营这项生意。
She flung herself into her career.
她投身于自己的事业中。