He looked relaxed and totally in command of himself.

他看起来很轻松，有绝对的自信完全能控制住自己。

For the first time in years, she felt in command of her life.

多少年来第一次，她觉得生活掌握在自己的手里。

Who is in command here?

这里谁负责？

I left a sergeant in command and rode forward to reconnoitre.

我留下一名警官主持局面，然后骑马出去侦察。

I'd never seen him like this, so sure of himself, so in command.

我从未见过他像这样，如此自信，如此得心应手。