How will the amount of fertilizer used on a field affect the number of earthworms found there? What is the independent variable?

What was different about warfare in the early 1800s and early 1900s?

Political boundaries are determined by the political party in control at all time true or false

How has the elimination of trade barriers affected the movement of goods among member countries of the european union? a. member countries are able to produce all the goods they need. b. goods can move freely among member countries. c. member countries no longer need to trade with countries outside the eu. d. larger countries are able to import more goods than smaller ones.