again and again基本解释
<英>再三地， 反复地；连声；累次；三番两次

again and again的用法和例句
The reason flu keeps infecting us again and again is that the virus is constantly changing .
流感能够反复感染我们的原因在于病毒的不断变化。

You know very well that you cannot make the bus come sooner by looking at your watch again and again .
你非常清楚的知道，即使你一再看表，也不能使车提前来。

That scenario has played out in my own life again and again .
同样的剧情在我的人生里一遍又一遍上演。