in a rut 慣性、因循苟且、墨守成規
說明：
在十六世紀晚期，rut 這個字是指馬車行走過所留下的軌跡。後來引伸為慣性的工作或習慣。in a rut 是 prepositional phrase，當形容詞用，動詞用 ve。
例子：
Tom is in a rut: he goes to work without knowing why.
People get locked in(to) a rut of trying harder without trying smarter.
His present job has put him in a rut.
by Thomas Shum