In summary, manual testing fills a gap in the testing repertoire and adds invaluably to the software development process.

总而言之，手工测试弥补了测试一览表之间的空白，对软件开发过程增加了极大价值。

The computer is an invaluably remorseless master: harsh, sometimes to the point of causing you to tear your hair out, but never unfair.

计算机可以说是一位铁面无情的大师：严酷，有时甚至会让你抓狂，但绝对公平。