资料来源 : pyDict

端坐,坐正;熬夜,不睡觉;大吃一惊,吓了一跳

资料来源 : WordNet®

sit up
     v 1: not go to bed; "Don't stay up so late--you have to go to
          work tomorrow"; "We sat up all night to watch the
          election" [syn: {stay up}]
     2: change to an upright sitting position; "He sat up in bed"