Why is the electoral college system do difficult to change

Look at the map of cities in the united states at the turn of the twentish century what impact did railroads have on cities across the united states at the turn of the twentish century

Space is not completely empty. there are small particles in space. what happens when these particles come together?

When there are advances in technology, such as the personal computer, how might business productivity change? a) productivity is separate from technological advances so there is no impact. the new technology can replace outdated, less efficient, machinery. o) the businesses' products will no longer be demanded. d) manufactured items will be made elsewhere.