Briefly define and give a specific example of:A.1.Scale economies in connection with urban economics (i.e., related to land use,housing, or firm location)A.2.Pecuniary agglomeration economiesA.3.Technological agglomeration economiesA.4.Retail agglomeration economiesA.5.ExternalitiesA.6.ceteris paribus assumptionA.7.A numeraire goodA.8.An efficient allocation of resources