 
 <translate> What was the question for this implicit rationale, and corresponding answer?
This is the relevant information: Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone, brick, or concrete; the steeper the gradient, the faster the flow.
 The answer: gravity <ibo> Gịnị bụ ajụjụ maka echiche a na-apụtachaghị ìhè, na azịza kwekọrọ na ya? Nke a bụ ihe ọmụma dị mkpa: Ọwa mmiri na-ebugharị mmiri site n'ike ndọda nanị, n'akụkụ ebe dịtụ ala n'ozuzu ya n'ime ọwa mmiri ndị e ji nkume, brik, ma ọ bụ ihe e ji ígwè rụọ rụọ; ka mkpọda ahụ dịkwuo elu, otú ahụ ka mmiri ahụ na-asọpụkwu ngwa ngwa.  Azịza ya bụ: ike ndọda. 