Idiomatics
成语学
🗣️ 情景例句
She's still giving the toughest English history exams
她仍用最艰深的英国史试题考学生
One thorn of experience is worth a whole wilderness of warning.
一次痛苦的经验抵得上千百次的告诫。
a wave length (the horizontal distance between two wave crests),
波长（两个浪峰间的水平距离）