(forgive and forget) - 原谅和忘记

(unprepared) - 措手不及

(unraveling) - 解开

(understanding) - 理解

(unfortunate) - 不幸的

(unending) - 无止境

(unconditional) - 无条件的

(undeserving) - 不值得

(unless...) - 除非...