But no one knows for sure when or why it began to symbolise peace. There is probably a connection with ancient Greece.

但无人确切知道在什么时候、或者是什么原因橄榄枝成了和平的象征，这有可能与古代希腊有关系。

youdao

Though pranksters and joke-lovers in many countries now gleefully prepare to dupe friends and loved ones on April Fool's Day, no one knows exactly when or why, or even where, this tradition began.

尽管很多国家的恶作剧达人和笑话达人正兴高采烈地准备在愚人节拿爱人和朋友开涮，但没有人知道这种习俗开始的确切时间、原因、甚至地点。

youdao

Though pranksters and joke-lovers in many countries now gleefully prepare to dupe friends and loved ones on April Fool's Day, no one knows exactly when or why, or even where, this tradition began.

尽管很多国家的恶作剧达人和笑话达人正兴高采烈地准备在愚人节拿爱人和朋友开涮，但没有人知道这种习俗开始的确切时间、原因、甚至地点。

youdao