[计] kirchhoff's law of conservation of flow

jī ěr huò fu liú shǒu héng dìng lù: ㄐㄧ ㄦˇ ㄏㄨㄛˋ ㄈㄨ˙ ㄌㄧㄡˊ ㄕㄡˇ ㄏㄥˊ ㄉㄧㄥˋ lu:4