1.serve as 充當,作為,用作
例句:Or it can serve as the go-between for your personal and career schedules.
或者它也可以作為你個人和工作時間表的中間人 。
2.warning sign 警告標志,預警信號
例句:Hearing things is a warning sign.
幻聽到聲音是個警示的預兆 。
3.keep...under control ...處于控制之下,被控制住
例句:They now require much less water to keep them cool and under control, and produce less steam.
它們現在只需要較少量水的來保持冷卻狀態,產生的蒸汽也更少 。