But Napoleon, by a stroke of luck, was able to build two new bridges.

侥幸的是，拿破仑居然突击造起两座桥。

Right on cue. What a stroke of luck.

说着说着就来了 多好的运气呀。

In a stroke of luck, a suitable organ donor became available.

【stroke】正巧，有了合适的器官捐献者。

So, it was by a stroke of luck that the head of Motown Records, Berry Gordy, heard about it.

因此，摩城唱片公司的负责人贝里·戈迪（Berry Gordy）听说了这件事，真是太幸运了。

And sometimes, these algorithms only discover the right answer by a stroke of luck – when something unexpected happens by good luck or chance.

有时，这些算法只能侥幸找到正确答案——侥幸是说一些意外之事刚巧或碰巧发生。