A satellite is any object that moves in a curved path around a planet. The moon is Earth's original, natural satellite, and there are many man-made (artificial) satellites, usually closer to Earth. The path a satellite follows is an orbit, which sometimes takes the shape of a circle.
To understand why satellites move this way, we must revisit our friend Newton. Newton proposed that a force -- gravity -- exists between any two objects in the universe. If it weren't for this force, a satellite in motion near a planet would continue in motion at the same speed and in the same direction -- a straight line. This straight-line inertial path of a satellite, however, is balanced by a strong gravitational attraction directed toward the center of the planet.
WHEN British and American people use the word family which normally consist of the mother, farther and their children. In a general social context, the "the family" is usually taken to mean this nuclear family.
Society in Britain and the US is traditionally based on a nuclear family living in the same house and closely involved in each other`s lives. Fifty years ago, the typical family was a husband and a wife, and two or three children. The father spent all day at work and made most of the decisions about how the money he earned was spent. The mother stayed at home to manage the house and look after the children. Children were expected to obey their parents.
Many modern families live rather differently, and because of this some people think that the family unit is dying and society is being weakened. Many couples still get married, but others live together without getting married. A few years ago, couples living together usually got married when they wanted to start a family, but this happens less now. Another trend is for people to get married later in life and to have fewer children, so the size of the average family is schrinking.
