Answer:
One could be in the cell. The cell respires, thus producing carbon dioxide in it. So the concentration builds up in the cell. Diffusion is the net movement of particles from a region of high concentration to a region of low concentration, and the carbon dioxide concentration outside the cell is less, therefore the carbon dioxide molecules moves outs of the cell.
Another scenario is when perfume is sprayed into the air. The perfume particles collides with the air particles (lower or no concentration of perfume). This process goes on and on. This is diffusion since the concentration perfume particles collides with the less concentrated particles of perfume.
The answer is A, friction.
Friction is the force that resists movement, and that's why oil is used as a lubricant and why ball bearings are used for machines that need to move with very little friction(i.e. bike wheels, roller skates, fidget spinners)
Answer B is too vague
C will probably reduce efficiency greatly, but not specifically in a way that turns work into thermal energy.
D is the same as C, except that it places the blame on the person using the machine, not the machine itself.
Hope I helped clear it up for you :)
The periodic table only accounts for elements. It does not account for compounds, such as water.
Answer:
Restoration of native plants and habitats on campuses can provide ecosystem services such as slowing storm water runoff and filtering pollution-c.