Most of the worlds urbanization has taken place in

travels along an axon. this triggers a wave of electrical activity that passes from the cell body along the length of the axon to the synapse

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.