这一观察是敏锐的，灵敏而尖锐。

The observation is ___acute, sensitive and sharp.

医生诊断他患有急性阑尾炎，需要立即手术。

The doctor diagnosed him with ___acute appendicitis requiring immediate surgery.

直角三角形有两个锐角。

A right triangle has two ___acute angles.

她对人际关系有着敏锐的洞察力。

She has an ___acute understanding of interpersonal relationships.