lucid

该哲学家对复杂问题作出了清晰的说明。

The philosopher gave a ___lucid account of complex issues.

她在半夜突然头脑清醒了片刻，一下子明白了如何解出这个方程。

She experienced a ___lucid moment in the middle of the night and suddenly understood how to solve the equation.

导游清晰的指引帮助迷路的游客们找回了山路。

The guide's ___lucid directions helped the lost tourists find their way back to the trail.