Answer the following in several complete sentences: A college professor wants to measure memory in elementary students before a vocabulary quiz. How could she operationally define memory?

Select the correct answer. what was edwin hubble's contribution to the field of astronomy? a. he discovered variable stars. b. he proved that the heliocentric model accurately described our solar system. c. he found a relationship between the period luminosity and distance of stars. d. he proved that the universe is finite. e. he discovered that the universe was expanding.