单丝不成线
dān​sī​bù​chéng​xiàn

one person alone cannot achieve much

  1. 单 單 dān adjective
    single
    single; individual; alone; separate
  2. 丝 絲 sī noun
    silk
    the fine thread produced by a silkworm; textiles made of silk
  3. 不成 bù​chéng
    to fail
    (bound form) to fail to happen; to not become something; to have no success or achievement
  4. 线 線 xiàn noun
    thread
    thread; string; wire; something long and thin like a thread; (bound form) made of cotton thread