D, because skin tans to help us stand being in the sun without getting burned.
An example of physiological adaption is being able to digest milk. Before, humans were not able to digest milk before we developed enzymes that now make us have the ability to do so, thus allowing us another food source.
<em>Answer:</em>
<em>van der Waals forces</em>
<em />
<em>Method:</em>
Online, and other sources to make sure the answer is correct.
The Earth comprises many spheres of subsystems, which associate with each other to develop a composite and spontaneously changing system of the Earth. The processes taking place in the system of the Earth occurs on spatial scales changing from fractions of millimeters to thousands of kilometers, and on time scales, which varies from milliseconds to billions of years.
The examples of instantaneous scales are a rotation of the Earth, breathing, an earthquake.
The examples of long-term scales are making coal and plate tectonics.
The system of the Earth is featured by various overlapping cycles in which matter is recycled again and again. The cycles involve interactions between multiple spheres and systems. The examples of cycles are rock cycle, day and night, and seasons.
Volcanoes discharge a huge concentration of particulate matter into the atmosphere. These particles function as nuclei for the development of droplets of water (hydrosphere). The rainfall, that is, hydrosphere usually upsurges after an eruption, initiating growth of the plant (biosphere). Thus, volcanoes and volcanic activities are a good illustration of system interactions.
A : DNA in the nucleus of the egg controls all cell activities
