This theme recurs several times throughout the book.这一主题在整部书里出现了好几次。Leap year recurs every four years.每四年闰年一次.The disease recurs in epidemic cycles at two - to three - year intervals .本病流行周期为 2-3年....

v.再发生，复发( recur的第三人称单数 )...

recurs的音标：...