那位目光锐利的老人一眼就发现了隐藏的钥匙。

The ___keen-eyed old man spotted the hidden key at a glance.

这位眼光敏锐的侦探立刻注意到了犯罪现场被忽视的微小细节。

The ___keen-eyed detective immediately noticed the tiny details at the crime scene that others had overlooked.