[追根溯源, zhuī gēn sù yuán, ㄓㄨㄟ ㄍㄣ ㄙㄨˋ ㄩㄢˊ]to pursue sth back to its origins; to trace back to the source; to get to the bottom of sth#59373[Add to Longdo]
[追根问底 / 追根問底, zhuī gēn wèn dǐ, ㄓㄨㄟ ㄍㄣ ㄨㄣˋ ㄉㄧˇ]lit. to examine roots and inquire at the base (成语 saw); to get to the bottom of sth#176397[Add to Longdo]