1. Once in the palace, it is as deep as the sea. Next sentence: From now on, I am a stranger in Xiao Lang.

2. Origin: A poem written by Cui Jiao, a poet in the Tang Dynasty, was given to a maid.

3. The original poem is as follows: the son Wang Sun followed in his footsteps, and the green beads wept and fell on the silk scarf. Once in the depths of Hou's ocean, he became a stranger from then on.

4. The son, the prince and the grandson fought back, and the beauty was wet with tears. Once he entered the deep back door, Xiao Lang became a stranger.