Answer:
Ventilation and mixing outdoor air with indoor air
Explanation:
All the deserts are found at 30<span>°N because
</span><span>Hot air from the equator rises, then cools, moisture is lost, and the dry air comes down at 30 degrees north and south</span>
The Answer is D. Tidal power because the waves created from the bottom of the ocean floor, the wave's never stop coming .