HELP! Solar, biomass, geothermal, wind, and hydropower energy are all renewable sources of energy. They are called renewable because they: a. Are clean and free to use

b. Can be converted directly into heat and electricity

c. Can be replenished by nature in a short period of time

d. Do not produce air pollution

C. Can be replenished by nature in a short period of time

Explanation:

Renewable, as a word, means that it is able to be replaced again. Renewable energy is energy that is able to be replaced quickly, and will never run out. Solar, biomass, geothermal, wind, and hydropower energy all can be reproduced again without the risk of running out, unlike fossil fuels.

Hope this helps!

Panna

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.