be strictly on guard against小心警惕地防范;严防
Be on your guard发现敌人了;你们应当谨慎;你们务要儆醒
to be on guard战兢;防范
be on guard to警惕
be on our guard戒备着
Be on guard against防范;小心防备;警戒;警惕
be on guard duty担负警卫任务
be on constant guard从旁监察注视
be on guard with警戒;详细翻译
I have pointed out this system抯 particular function to be on guard against the Han officials besides preventing feudal separatist rule, containing economic and judicial corruptness, cracking down on cliques.
第三部分从历史特点和历史局限两个方面对清代前期回避制度进一步作出了理论的概括和评价,指出它除了防止地方割据、遏制经济和司法腐败、打击朋党之外,尚具有其特定的作用,即防范汉员。
参考来源 - 清代前期回避制度述评