人所共知

rénsuǒgòngzhī
something that everybody knows

CEDICT

to be known by everyone; to be common knowledge

Wiktionary

所有人都知道

維基詞典

Entry Composition

1 人 rén person; people

classifiers: 個, 位
2 所 suǒ
  1. actually
  2. place
  3. classifier for houses, small buildings, institutions etc
  4. that which
  5. particle introducing a relative clause or passive

classifier: 個
3 共知 gòngzhī
  1. (literary) mutual understanding and participation
  2. mutual understanding and participation