Final answer:
Boys' study habits included reading, writing, math, music, and physical education classes in preparation for military service. Later, compulsory army service at 18 years of age.
Step-by-step explanation:
The boys in this context were educated at home until the age of seven and then began formal schooling.
Their study habits included subjects such as reading, writing, mathematics, and music, as well as physical education classes to prepare for future military service.
It was also compulsory for them to serve in the army at the age of 18.