You must obey the captain's commands.

你必须服从船长的命令。

《牛津词典》

He must obey it instantly, and go.

他必须立即服从命令，然后前往。

youdao

You must obey orders.

你非得服从命令不可。

《新英汉大辞典》

"You know my rule,Andy. In all illegal activities, we must obey the law, in every detail.

VOA: special.2010.04.24

In other words, to make people obey you, you must first make them believe you.

换句话说即要让人们服从你，必需要先让他们相信你。

耶鲁公开课 - 政治哲学导论课程节选

That means most schools must obey a federal law known as Title Nine.

VOA: special.2010.03.04

God has sent her to do this, she says, so she must obey.

ECONOMIST: Uganda

Neil Austrian, the league's president, says no: If 24 teams vote to renew the agreement, all 31 teams must obey.

FORBES: Cowboy capitalism

The guidance talks about civilian casualty mitigation (CCM) primarily as a strategic consideration, rather than as a legal obligation that soldiers must obey.

FORBES: More on Preventing Harm to Civilians