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.
Focus strategy is just what it sounds like: concentrate on a particular customer, product line, geographical area, market niche, etc. The idea is to serve a limited group of customers better than your competitors who serve a broader range of customers. A focus strategy works well for small but aggressive businesses.