The correct option is this: A STRONG WIND BLOW ACROSS A MIDWESTERN PRAIRIE.
A strong wind is an example of a natural force. The prairie refers to a land fill with grasses and that is a natural factor also. Thus, a strong wind that is blowing across a prairie is generating a natural form of energy. The energy flow in the other options given are examples of man made devices.
Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
Well if you were to ask me 1 is that sporulation can make lots of more plants but i dont know any disadvntages
Osmosis is the movement of water particles from an area of high concentration of water particles to an area of low concentration of water particles across a semi permeable membrane
Diffusion is the movement of particles from an area of high concentration of particles to an area of low concentration of particles across a partially permeable membrane
Plasmolysis is the shrinking of the cytoplasm if a plant cell in response to diffusion of water out of the cell and into a high salt concentration solution as the cell membrane would pull away from the cell wall
Hope this helped
Natural selection helps the anteater get food easier than others.