lo

lo
/ləu; lo/ interj
1 (arch 古) look; see 看; 瞧.
2 (idm 习语) ,lo and be`hold (esp joc or ironic 尤作戏谑语或作反语) (used to indicate surprise 用以表示惊讶)
    As soon as we went out, lo and behold, it began to rain. 我们刚一出门, 你瞧, 就下起雨来了.

牛津英汉双解词典