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

Plants can have a positive and negative effect on the rate of weathering

Which statements about wells are true? check all that apply. a) wells bring groundwater from the unsaturated zone to the surface of the water. b) wells need to be drilled below the water table. c) if water is pumped from a well too quicky, the well may run dry. d) water from wells is generally not safe to drink. e) water gushes from artesian wells due to pressure.

The nations of indochina a. share a common langauge b. share a common history c. share a common religion d. none of the above