单词：again_and_again 

副词

• 
  [1.r.again_and_again] (同义词:[over_and_over(adv.反复, 再三 )]  [again_and_again(adv.再三地, 反复地 )]  [over_and_over_again(adv.一再地 )]  [time_and_again(adv.反复地 )]  [time_and_time_again]  )
• 
  注释列句：repeatedly; "the unknown word turned up over and over again in the text"