do his duty

• vi. 尽职(尽本分；尽义务)

do his duty的用法和样例：

例句

1. He who does his duty is worthy of praising.
   凡是忠于职守的人都值得奖励。
2. He who does his duty is worth praising.
   凡是忠于职守的人都值得赞扬。