Natural selection helps the anteater get food easier than others.
These would be the elements in row 2 the alkaline metals. Elements in a row usually share many qualities such as electon reactivity as well as similar characteristics like the fact that many alkaline metals are considered Cations, ions with positive charges. Some examples are beryllium and calcium.
The difference between analog and digital signals is that an analog signal is a continuous electrical message while digital is a series of values that represent information. Analog is conveyed by electrical current variations.
i dont understand what you are saying but water gets evaporated from the oceans due to the suns warmth all the water vapors condense, once the clouds get too heavy and there are too many water vapors in the cloud for it to handle, it percipitates (rains)