Options:
+ Earthquakes and nothing else.
+ Only wind.
+ Wind causes most waves.
+ Wind causes some waves.
Q: Read the following article and answer the question. Article: Wind is the great maker of waves. There are exceptions , such as the tidal waves sometimes caused by earthquakes under the sea. But the waves most of us know are caused by winds blowing over the sea . Now let's learn some physical things about it. A wave has height, from low point to high point . It has length --the distance from this high point to that of the following wave. The period of the wave means the time it takes for succeeding high points to pass a fixed point. None of these things stays the same--for all depend upon the wind, upon the depth of the water and many other matters. The water that makes up a wave does not advance with it across the sea. Each drop of water turns around in a little circle with the passing of the wave, but returns very nearly to its original position . And it is lucky that this is so. For if the huge groups of water that make up a wave really moved across the sea, sailing would be impossible. If we want to find the speed of a wave, we may use the following way : Speed =" wavelength" x frequency . Here, wavelength is the distance between two high points , frequency means the number of cycles per second Question: What causes waves? Answer:
A:
Wind causes most waves.