Any foreign material that can get inside your body and make you sick is called a

What are the characteristics of living things

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