Answer:
An author of a high school textbook may choose to emphasize Soviet cultural achievements such as ballet for a few reasons. First, it is important for students to understand the cultural and historical context of a given time period, and Soviet ballet was an important aspect of Soviet cultural and artistic achievement during the 20th century.
Step-by-step explanation:
In summary, an author of a high school textbook may choose to emphasize Soviet cultural achievements like ballet because it represents an important cultural and historical context, a unique intersection of art and politics, and an influential contribution to the development of ballet as an art form.