Which of the following body systems does the immune systems rely on to provide the first line of defense against pathogens?

A. Integumentary system

B. Nervous system

C. Circulatory system

D. Endocrine system

Is the eccentricity of planet orbits closer to 1 or 0?

Why might DNA mutation occur?

A cheetah ran 100 meters in 6 seconds. what is its average speed?

Which of the following has the most inertia, if they all travel at 5 m/s? A. A cat B. A bicycle C. A child D. An elephant

Ike is cutting the grass using a human-powered lawn mower. he pushes the mower with a force of 45 n directed at an angle of 41° below the horizontal direction. calculate the work that mike does on the mower each time he pushes it 9.

How did Einstein's and Newton's theories differ in terms of explaining the cause of gravity?

A sled being dragged to the right across loosely packed snow with a rightward acceleration

Imagine two artificial satellites orbiting earth at the same distance. one satellite has a greater mass then the other one which of the following would be true about there motion? 1.

What is energy? (Not the answer from google search.)

Explain why the friction force between two surfaces increases if the force is pushing the surfaces together increases.