Why did europe not see roman-era numbers of men participating in battles until the 17th century?

In 1958, the aarp was organized to promote

The congress shall have power to lay and collect taxes, duties, imposts and excises, to pay the debts and provide for the common defence and general welfare of the united states . .; to borrow money on the credit of the united states; to regulate commerce with foreign nations, and among the several states, and with the indian tribes. —constitution of the united states, article i, section 8 which of these are expressed powers granted by this part of article i, section 8? check all that apply. lay and collect taxes and duties pay debts regulate american indian groups regulate commerce within states borrow money regulate commerce with foreign nations

Which of harriet martineau’s books is a foundational treatise on sociological data collection?