Which of the following is an example of the skeletal system interacting directly with the
respiratory system?

a the ribcage expands to allow air to enter the lungs.
b the muscles attached to bones contract to lift your leg.
c the marrow inside bones produces white blood cells.
d the vertebrae protect the spinal cord from injury,

Which of the following protists gets nutrients mainly by absorbing molecules from other organisms through their cell walls and cell membranes? a. amoebas b. water molds c. ciliates d. slime molds

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.