Which of these animals is a marsupial?
a. elephant
b. echidna
c. dolphin
d. kangaroo

The hypothesis of continental drift states that earth's continents, which are located on tectonic plates, move relative to each other. which of the following is true of the movement of the tectonic plates? a. tectonic plates only move once every million years. b. they move at a rate of approximately 5 centimeters per year. c. tectonic plates never move, only the continents located on them do. d. their movements are very rapid and occur at random times.

Nucleic acid certain protein cell membranes certain carbohydrates

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