Three parts.

1. The first part (1-2): Describes the hardships of the Red Army crossing the grassland, and the scene of the old squad leader accepting the task of leading the sick patients. This part lays the foundation for the entire story and allows readers to understand the story background and character relationships.

2. Part 2 (3-5): This is the core part of the whole story, which depicts the touching deeds of the old squad leader fishing and making fish soup to take care of the sick. This part shows the old squad leader's selfless dedication and caring qualities through detailed descriptions, making readers admire the old squad leader.

3. The third part (6-7): Describes the scene of the old squad leader’s sacrifice, as well as the young patient’s memory and gratitude to the old squad leader. This part allows readers to feel the cruelty of war and the beauty of human nature, while also emphasizing the themes of friendship, love and dedication.