What scientist first proposed that the sun is the center of the solar system?
a. brahe
b. kepler
c. ptolemy
d. copernicus

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

How did the movement of soldiers during world war 1 contribute to the global influenza (flu) pandemic of 1918 to 1919, which killed millions of people

In north america, most winter storms form when cold, dry air from interacts with warm, moist air from