1 sentence

1. 训练演习是一回事，真正的行动则是另一回事。

   xùn​liàn yǎn​xí shì yī​huí​shì, zhēn​zhèng de xíng​dòng zé shì lìng​yī huí​shì.

   Training exercises are one thing, real operations are something else.

   Source: CCMatrix