by chance

　　英 [baɪ tʃɑːns]   美 [baɪ tʃæns]

　　偶然，碰巧；意外地

　　例句

　　I saw the letter purely by chance.

　　我看见这封信纯属偶然。

　　I met him by chance out walking yesterday

　　我昨天外出散步时碰巧遇见了他。

　　Although we have only met by chance， I can see you are a very remarkable girl with a clear purpose in life.

　　虽然我们萍水相逢，可是我觉得你是个了不起的有志气的姑娘。