What do you mean by quatrains?

1. The poem "Jueju" means that two orioles are singing at the head of green willow branches, and a row of egrets fly into the blue sky. The scenery of Xiling Snow Mountain seems to be embedded in the window, and ships coming and going to Soochow are parked by the door.

2. The original text is as follows:

"Two orioles sing green willows, and egrets cover the sky."

My window framed the snow-covered western hills. My door often says "goodbye" to ships sailing eastward.

3. Creative background