They were alarmed by a sudden attack.

突然袭击使他们大为惊恐。

youdao

Be careful when handling a sudden attack of heartburn as it can be a signal of something even worse.

要小心处理突然袭击的心，因为它可能是一个信号的东西更糟糕。

youdao

I had a sudden attack of acute myocardial infarction at home and had first-aid treatment for about 3 hours at the spot prior to admission.

我在家里突然发生急性心肌梗死，入院前在现场抢救了3个小时。

youdao

A seizure is a sudden attack that may affect a person's mind or body for a short period.

VOA: special.2010.10.26

The Intensive Care Unit (ICU) where sickle cell patients go for treatment when suffering a sudden attack lost all five of its consultants and one of them is still in jail.

BBC: Bahrain sickle cell death rise causes concern

In 1970, both men died, the salesman, of a sudden heart attack on a tennis court, and the professor, of cancer.

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He died Wednesday of a sudden heart attack.

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