Which statement describes the process of subduction? A. Convection currents pull a plate into the mantle.
B. One plate slides beneath another due to gravitational pull.
C. Materials are transferred within Earth’s interior by density.
D. Heat cycles in the mantle cause plates to constantly move.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.