User: The greenhouse effect is a result of A. absorption and radiation of energy in the hydrosphere. B. consumption of fruits and vegetables that produce a biofuel. C. absorption and radiation of energy in the atmosphere.
A principal focus or focal point is a special focus: 1  For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal pointsâone on each side.
You're likely to have a promotion focus. You're starting with nothing and your goal is to gain points. Imagine, on the other hand, I tell you that you're starting with 10 points, and for each of 10 questions, you lose a point for each answer you get wrong. In this case, you will have a prevention focus.