他对工作的热情让同事们都很钦佩。

His ___keenness for work impressed all his colleagues.

这把刀的锋利程度足以轻松切开厚纸板。

The ___sharpness of this knife can easily cut through thick cardboard.

她对细节的敏锐观察力使她成为一名出色的侦探。

Her ___keenness for details made her an excellent detective.