104. boil down to: 重点是，将……归结为 The southern issue boils down to lack of trust. 南方问题归根结底是因为缺乏信任。
105. end up + doing something/某种状态: 最终，结果 He will end up in prison. 他早晚得进局子。 You might end up getting something you don't want. 到头来你可能得非所愿。
106. hit upon/on something: 突然想到，灵机一动；偶然发现 She hit upon a good idea. 她突然想到一个好主意。 hit on a path to the pound 偶然找到了一条通往池塘的小路 表“突然想到”： An idea hits/strikes her. It occurs to someone that; something comes/springs to mind; something crosses someone’s mind
107. grow out of: 产生于，源于 The idea of this book grew out of a conversation. 创作的想法来源于一次谈话。
