spontaneous [spɑ:nˈteɪniəs]

例句:

• An irreverence which had not been premeditated but spontaneous.
  来自J. Agee
• The eruption of a volcano is spontaneous.
  火山的爆发是自发的。
  来自《权威词典》
• Her successful jump brought a spontaneous cheer from the crowd.
  她成功越过横竿后,观众立即发出一阵欢呼声。
  来自《权威词典》
• I had another spontaneous miscarriage at around the 16th to 18th week.
  我在大约第16至18孕周时又经历了一次自然流产。
  
• spontaneous outpourings of praise
  一片自然迸发的赞美声
  
• a spontaneous offer of help
  主动提出帮助
  
• Her charities were...often spontaneous, though perhaps somewhat scenic.
  来自fig.
• Mobility problems may also result from these spontaneous bleeds.
  来自BBC