这把剪刀的刀片非常锋利，很容易就能剪开厚纸板。

The ___sharp blades of these scissors can easily cut through thick cardboard.

这位教授思维敏锐，总能抓住问题的核心。

The professor has a ___sharp intellect and always grasps the core of issues.

他突然转变了话题，让大家都感到意外。

He made a ___sharp change of topic, surprising everyone.

月光在湖面上投下清晰的分界线。

The moonlight cast a ___sharp dividing line on the lake surface.

这种柠檬汁太酸了，我的舌头都麻了。

The lemon juice is so ___sharp that it makes my tongue tingle.