acute

critical, acute, urgent

这些形容词均有“紧急的”或“严重的”之意。
critical: 指极为危急或缺乏的状况，而这种状况标志一种转折点。
acute: 通常指需要和缺乏的紧急程度。也指病情的严重。
urgent: 指情况紧急，急需解决问题。

keen, acute, sharp, shrewd

这些形容词均有“锐利的、敏锐的、机敏的”之意。
keen: 多指对复杂艰深的事物或问题有敏锐的观察和敏捷的理解。
acute: 侧重感觉敏锐，能分辨出一般人难以觉察的细微区别。
sharp: 指人头脑精明、敏锐或机警。
shrewd: 指有头脑，善于判断分析，精明过人。

名词 acute:

1. a mark (') placed above a vowel to indicate pronunciation
   同义词：acute accent, ague

形容词 acute:

1. having or experiencing a rapid onset and short but severe course
2. extremely sharp or intense
   同义词：intense
3. having or demonstrating ability to recognize or draw fine distinctions
   同义词：discriminating, incisive, keen, knifelike, penetrating, penetrative, piercing, sharp
4. of an angle; less than 90 degrees
5. ending in a sharp point
   同义词：acuate, sharp, needlelike
6. of critical importance and consequence

1. The patient is complaining of acute earache.
   病人说耳部剧痛。
2. He suffers from acute depression.
   他患有严重的抑郁症。
3. She has acute hearing.
   她有很敏锐的听力。
4. We agreed with his acute analysis of the political situation.
   我们都同意他对政治形势的深刻分析。
5. This area has an acute shortage of water.
   这个地方缺水严重。