He is as cool as a cucumber.

他是个相当冷静的人。

youdao

She was as cool as a cucumber before the big test .

她在大考之前很冷静镇定，毫不紧张。

youdao

I know my father — he will be as cool as a cucumber.

我了解我父亲——他会保持冷静的。

youdao

You might say a person is as cool as a cucumber if he never seems to worry about anything and stays calm in a stressful situation.

VOA: special.2011.02.13

Jutting out of London's skyline in all its futuristic glory, the "Gherkin" building has managed in the last few years to embed itself in the city's psyche as an icon, an edifice that just looked as cool as a cucumber.

FORBES: Magazine Article

He was cool as a cucumber in his seersucker suit.

CNN: Mardi Gras 2006