What happens in the 15th chapter of red scarf girl?

The Rice Harvest Over the summer, middle school students are forced to perform Summer Labor. Chang Hong, Ji-li's friend and classmate convinces Ji-li to go into summer labor on the countryside. She agrees when she learns it would help in her in remolding. Ji-li arrives in a farm in the countryside with some of her classmates. Ji-li's job is to harvest rice in the fields. The work is backbreaking labor and Ji-li is in much pain, but she's determined to finish. Bai Shan tries to help her finish but she stubbornly refuses to let him. The next day, she faints from heat stroke, while loading rice into a thresher. Later, she learns from Chang Hong that she is returning to Shanghai to complete a study session with her father's theater. She does not return to the rice field again.