Cross-sectional research studies gather data from many people who are of the same age and compare them to others who are at a different age and thus a different level of development. the name for a group of people who are the same age and thus were raised during the same time period is a/an

Match each theory with its description. 1. oscillating universe theory 2 the universe came from a very dense, very hot "fireball" that exploded and expanded into existence. 2. inflation theory 3 the universe is a never-ending cycle of big bangs and big crunches. 3. big bang theory 4 the universe has always been and continues to be the same. 4. steady state theory 1 a very, very fast expansion and acceleration of the universe happened milliseconds after the big bang.