A long period of climate cooling during which ice sheets spread beyond the polar regions is called a

Seed plants that lived during the carboniferous impact life on earth today because a. they are the ancestors of all plant life on earth. b. their remains formed coal, which is an important resource. c. they produced fossils that are used to date many geologic events. d. their presence caused oxygen levels to drop, allowing animals to evolve.

The point where two air masses meet is called a

Astudent conducts an experiment to see how music affects plant growth. the student obtains four identical plants. each one is potted in the same type of soil and receives the same amount of sunlight and water each day. plant a listens to classical music for three hours each day. plant b listens to rock music for three hours each day. plant c listens to country music for three hours each day. plant d does not listen to any music at all. 2. based on the experiment in the scenario, which visual aid would be most in showing the change in the plants' heights over time? a. a pie chart b. a line graph c. a timeline d. a bar graph