Traffic has become synonymous with air pollution, and many countries intend to ban the sale of new petrol and diesel cars in the next two decades.
2019年12月六級(jí)真題（第二套）閱讀 Section A
柯林斯高階英漢雙解學(xué)習(xí)詞典釋義
ADJ
(與…)關(guān)系緊密的;等同(于)…的;互為依存的
If you say that one thing is synonymous with another, you mean that the two things are very closely associated with each other so that one suggests the other or one cannot exist without the other.