This should be valence electrons. They determine the chemical properties of an atom.
Gravity is the force that pulls us to the surface of the Earth, keeps the planets in orbit around the Sun and causes the formation of planets, stars and galaxies.
<span>Either A or B.
Humans don't go through the process of photosynthesis, plants do.</span>
The facial feedback theory is a psychological theory associated with the emotional consequences due to physiological actions.
The provided case study a number of smiling faces which made the person saying it smile thereby working there muscles that related with smile this makes a psychological consequence and people find things much more funnier than they usually are.
If as a viewer again this case study is provided and the viewers is allowed to mimic in mirror he or she will again make much funnier faces due to the psychological consequence.
I think that the answer is D.
