prevent       
verb [ T ] uk/prɪˈvent/ us/prɪˈvent/
B1 阻止,妨碍;预防
to stop something from happening or someone from doing something
  Label your suitcases to prevent confusion. 在你的手提箱上贴上标签以防弄混。 
 [ + -ing verb ] His disability prevents him (from) driving. 他有残疾,不能开车。 
 - More examples
 - The police seem to be powerless to prevent these attacks.
 - She would go over the accident again and again in her mind, wishing that she could somehow have prevented it.
 - A block in the pipe was preventing the water from coming through.
 - Fierce winds prevented the race from taking place.
 - The law has done little to prevent racial discrimination and inequality.