She mostly took a tumble—but it's no surprise her first instinct was to protect her husband.

她差点摔倒——但不难理解，她本能的第一反应就是保护自己的丈夫。

youdao

His first instinct was to run away.

他的本能反应就是逃跑。

《牛津词典》

I should've gone with my first instinct, which was not to do the interview.

我应该凭我的本能反应行事，那就是，不去面试。

《柯林斯英汉双解大词典》

The interesting question is why your first instinct is to reject these facts as irrelevant.

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During economic crises her first instinct has been to double the guard around the German treasury.

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We figured either an airplane had hit it or -- our first instinct was an airplane.

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