What is the primary source of fuel for the brain?
a. proteins
b. fats
c. carbohydrates
d. vitamins

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

What is the "great pacific garbage patch"? a large area of marine debris concentrated by rotating ocean currents a large area around the pacific rim where debris collects from natural disasters such as tsunamis an area in the pacific ocean where trash is intentionally dumped due to lack of landfill availability a large trash dump located in hawaii

What are the most explosive events that occur on the sun? umbras solar flares solar winds prominences