happen upon

基本解释

But if scientists happen upon pure fusion, who knows what they might do with it?
但是如果科学家开启上面的纯核聚变反应堆，谁知道他们可能会用它来做什么？
But now, if you happen upon an old episode, Elaine just looks cool — and of-the-moment.
不过如果你现在正巧看到一集“宋飞正传”的老片段，你会发现“伊莲”看起来好极了，而且很时髦。
Turn a corner and you will happen upon the startling green of the winter harvest, of men bending over paddy fields with nothing for tools but their bare hands.
拐过一个弯，冬天里令人称奇的绿色沃野扑面而来，农人们没有工具，全凭双手在稻田里躬身劳作。

Just as your lover's caress brings you to orgasm, your eyes happen to fall upon a shoe.
正当情人的爱抚使你进入高潮的时候，你的目光恰巧落在了鞋子上。
耶鲁公开课 - 心理学导论课程节选

Fortunately, the case of Mvscles and Muscles is merely a strange occurrence when people oceans apart happen upon a few seconds of pop panache that sound eerily similar.
FORBES: Boston Electronic Duo Mvscles And The Case Of Musical Coincidence
Pulling out the battery is the only option for recovery, so if you happen upon a scene that you want to capture right away, having a camera that occasionally fails is far from ideal.
ENGADGET: Pentax Q interchangeable lens camera review Hands-on