Airline frequent flyer programs that reward customers with a free flight after every 75,000 miles of travel illustrate the use of a schedule of reinforcement.

What trade did europeans want most before the 1800s ivory wood slaves gold

Which statement is not true about the missouri compromise? 1.) slave owners could pursue escaped slaves into “free” regions. 2.) maine entered the union as a free state. 3.) slavery was allowed throughout the louisiana territory. 4.) missouri entered the union as a slave state.

Did egypt invent wheels or sailboats