了无瓜葛 have nothing to do with：That politician claimed that he had nothing to do with that scandal.
力不从心 my spirit is willing, but my flesh is weak：A:Can you do me a favor? B:Sorry, my spirit is willing, but my flesh is weak.
力挽狂澜 try to stem the tide：He tried to stem the tide, but in vain.
入境随俗 Do in Rome as the Romans do.
入木三分 It actually gave a vivid picture of cut the quick. (leave an indelible impression)
七上八下 to be sixes and sevens：Don't talk to me now because I am all at sixes and sevens. (with one's heart going pitapat)
七窍生烟 He was in a great fury (fuming with anger; in a great rage; terribly furious) and swore to get even with the opposite(跟对方报复).
七零八落 After the quake, the buildings went to rock and ruin.
八面玲珑 smooth and able to win favour on all sides.
小Car笔记：
in vain：徒劳
all sides：各方面