Final answer:
The question concerns the high casualty numbers of World War I offensives, with millions of casualties reported in battles like Verdun and the Somme, reflecting the devastating human cost of the war.
Step-by-step explanation:
The question refers to the incomprehensibly high death toll during certain offensives in World War I, specifically those in 1915 that had negligible territorial gains. During World War I, many battles resulted in massive casualties with minimal strategic advantage, and while the question specifically asks for 1915, there were several significant battles throughout the war with high casualties. For example, the Battle of Verdun in 1916 resulted in 540,000 French and 430,000 German casualties. The Battle of the Somme in the same year led to the death or wounding of an astounding 60,000 soldiers on its first day, with eventual totals of 420,000 British, 200,000 French, and 650,000 German casualties. Other offensives such as the Brusilov Offensive and the Spring Offensive also saw casualties in the millions. The overall tragic loss of life during World War I highlights the sheer destructiveness of the conflict, with up to 19 million soldier deaths and an additional 7 to 8 million civilian deaths resulting from the war - before the devastating influenza pandemic of 1919.