1. Waves are created when a source of energy causes a .

Waves are created when a source of energy causes a medium to vibrate. A vibration is a repeated back-and-forth or up-and-down motion. This motion is the source of the wave. Waves are classified according to how they move.

Explanation:

the correct answer is economics is a game without winners or losers.

unlike sports or games economic is a game without losers or winner rather it is a game where everyone wins. parties of business doing businesses exchange money with each other and hence exchange is done on the basis of goods. one party takes the goods and other sales it so there is winner on both sides. each party values more highly the good it gets than the good it gives up. both sides exchange only because both intend to increase their value. so there is no concept of lose or win.