a stroke of lightning.的用法和樣例：
例句
- Harry was left with a scar in the shape of a lightning bolt on his forehead.
哈里前額留下了一個閃電形狀的疤痕。 - A flash of lightning lit up the huddle of huts, and in the brilliant white glare she could see a number of people hurrying through the downpour.
一個閃電照得這一帶的草棚雪亮，閃電光下看見大雨中有些人急急忙忙地走。
