大敌

tā rèn wéi gǎi gé shì gé mìng de dà dí

他认为改革是革命的大敌。

He thought that reform is the arch enemy of revolution.

zǒng tǒng jìn xíng guó shì fǎng wèn qī jiān bǎo ān bù mén rú lín dà dí

总统进行国事访问期间保安部门如临大敌。

A huge security operation was mounted during the president's state visit.