Lightning never strikes the same place twice.

“闪电从不打同一个地方”，与我们说的“福无双至，祸不单行”恰恰相反，这也是差异的一个有趣的体现。

例如：
-How were your exams? All over?
-I really don’t know. I did rather poorly last time. I hope I’ll do better this time.
-Come on， don’t worry about it。 You are sure to pass。 As the saying goes， lightening never strikes the same place twice.
One swallow does not make a summer.

swallow 是燕子。西谚说，一只燕子飞来不能代表夏天的来临。而中国成语却说， 一叶知秋。两种说法各有其智慧。“One swallow does not make a summer”强调的是要区别一般性与特殊性的辩证哲理； 而“一叶知秋”体现的则是从细微的端倪窥见总体趋势的睿智。

例如：
-Hey， look! The scores are already 2:1！Liverpool is sure to win， I bet!
-I don’t think so. One swallow does not make a summer. Miracles always happen the last minute.