The skeletal system is the framework of the human body, comprised of bones, joints, and connective tissue. The integumentary system forms the largest system of the human body and is made up of skin, hair, nails and glands. How do the skeletal and integumentary systems work together to protect the human body? A. The two systems initiate muscle contractions that protect the human body.

B. The two systems provide a barrier between the outside environment and the internal organs of the body.

C. The two systems initiate an immune response that protects the human body.

D. The two systems deliver signals between the outside environment and brain.

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?

If the rna molecule in a human has the nucleotide sequence of guu, this would the amino acid valine would be needed to make the protein. how would this cha process was occurring in a mushroom?

Which of the following are not included as modern mammals that evolved during the eocene epoch? primates artiodactyls perissodactyls none of the above