A "loud sigh" means she thinks you are an idiot at that moment, and wonders why she is wasting her time standing here arguing with you over "Nothing".

一声“大声叹息”意味着她认为那一刻的你是一个白痴，而且不明白自己为什么浪费了这么多时间站在这里来跟你争论“无关紧要的事”。

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She loves to run, but wonders why.

她喜欢跑步，可不知道为什么。

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Mom wonders why I'm suddenly curious about family history.

妈妈很奇怪，为什么我突然对家族史这么感兴趣。

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He wonders why loved ones can't wait together in America while visas are being processed.

NPR: A Family's Wait for U.S. Visas Spans Generations

Cheung's husband wonders why she pays to work for others, even if it is deductible.

FORBES: Magazine Article

Simpson still wonders why bottles, especially clear and green, are still used at all.

FORBES: Bottle Or Can? The Great Beer Debate Rages On