尽管年事已高，他对商业策略仍有敏锐的头脑。

Despite his age, he still has a ___sharp mind for business strategies.

我祖母可能身体虚弱，但她仍保持着异常敏锐的头脑。

My grandmother may be frail, but she retains a remarkably ___sharp mind.

要解决复杂的谜题，你需要敏锐的头脑和极大的耐心。

To solve complex puzzles, you need a ___sharp mind and great patience.