Which of the following features does not improve the rate of diffusion?
a. thin membranes lining respiratory organs such as gills and lungs
b. multiple infoldings of respiratory surfaces, such as lamellae in gills
c. inhaled fresh air is mixed with old air from the previous breathing cycle
d. blood circulates in counter current direction to water flow in gills

as many times as you want

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies

the most common energy conversion is from kinetic energy to potential energy, and then from potential energy to kinetic energy.

later on comes the heat energy, mechanical energy, and other energy conversions.

this energy conversion is so common that we can find it in our day to day lives as well.

- one of the most common energy conversions involves the changing of potential energy to kinetic energy or kinetic energy to potential energy