Vacillator
n. 踌躇;犹豫;动摇
🗣️ 情景例句
But it is not polite to ask older people their age.
但问老人的年龄是不礼貌的。
Often and little eating makes a man fat.
少吃多餐，身强体胖。
a wave length (the horizontal distance between two wave crests),
波长（两个浪峰间的水平距离）