沿波讨源沿流讨源yán bō tǎo yuántrace the water and search for its source—trace the source according to the clues
❍ 如果你～，问题终究是会得到解决的。If you trace the source according to the clues,the problem will be solved eventually. 沿波讨源yán bō tǎo yuán沿着水流寻找发源地。make a thorough investigation of a thing, trace the source according to the clues |