Refraction occurs when a wave changes its a) color. b) frequency. c) intensity. d) speed.

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

The scales shown in the introduction measure mass, or the amount of matter in a particular object. the scientific law of conservation of mass states that matter cannot be created or destroyed during a chemical reaction, but it can change from one form to another. did the simulation support this scientific law? explain why or why not.