Plz, answer my previous question!

The nursing instructor has been observing nursing students initiate an iv infusion. which action(s), if made by the nursing student, indicates that further instruction is needed? (select all that apply.) the nursing student:

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

What materials must dams have to produce electricity, and what must occur?