独木难成林 (獨木難成林) dú mù nán chéng lín

dú mù nán chéng lín set phrase a lone tree does not make a forest
Domain: Proverb 谚语
Notes: Variant of 独木不成林; one cannot accomplish much on one's own (CC-CEDICT '獨木不成林'; Guoyu '獨木不成林')