突然他发觉自己醒了过来，而且高度警觉。

Suddenly he found himself awake and fully alert.

《牛津词典》

突然他醒了过来而且高度警觉。

Suddenly he woke up and was fully alert.

youdao

有些事情可能会出错，这需要人们保持一种高度警觉的状态。

The possibility that something could go wrong required a state of hyper-awareness.

youdao

对此要保持高度的警觉。

Be alert to this.

youdao

对此要保持高度的警觉。

Be alert to this.

youdao