Through the heart: refers to extreme grief and indignation in the heart.

Stabbing the heart and cracking the liver: refers to extreme grief.

Bitter and unforgettable: ① unforgettable so far. Refers to the deepest feelings. 2 It is also called "stabbing the heart and cutting the bone". I am extremely sad and angry.

Thorn on the top and change on the bottom: satirize the monarch and educate the people.

Holding a snipe with a thorn: a metaphor for waiting for an opportunity to kill two birds with one stone.

Study hard: a metaphor for studying hard.

Thorn: the appearance of many words. Describe nagging, endless.