Answer:
trading was park of Uruks economy.
The opinions and prejudice of an author in writing.
I believe that those two elements greatly affect bias in history because we can never be 100% sure of everything that (may have) happened in history (especially farther in the past), so opinion can affect a historian's writings. Also, everyone is prone to some sort of prejudice, so this can also affect history.
The Central American Vegetation/Land Cover Classification and Conservation Status consists of GIS coverages of vegetation classes (forests, woodlands, savannas, shrubs, grasslands, wetlands, rocks, sand, soils, inland waters, parks and reserves) for Central America, derived from 1-kilometer resolution Advanced Very High Resolution Radiometer (AVHRR) imagery. This data set is produced by Proyecto Ambiental Regional de Centroamerica/Central America Protected Areas Systems (PROARCA/CAPAS), a conservation partnership of the Central American Commission on Environment and Development (CCAD), U.S. Agency for International Development (USAID), International Resources Group, Ltd. (IRG), The Nature Conservancy (TNC), Winrock International (WI), and is distributed by the Columbia University Center for International Earth Science Information Network (CIESIN).
