Tides are caused mainly by ____________ in how much the moon’s gravity pulls on different parts of Earth. The force of ___________ pulls the moon and Earth toward each other. The moon’s gravity causes ____________ tide on the side closest to the moon. The moon’s gravity pulls Earth, leaving water behind causing an additional high __________. _________ tides occur between the two high tides. There are _________ low tides and _________ high tides a day. Their combined forces produce a tide with the greatest difference between consecutive ______ and ______ tides, called a spring tide. Spring tides occur ________ a month, at new moon and at full moon. During the moon’s _______-­‐quarter and third-­‐
quarter phases, the line between ________ and the sun is at _______ angles to the line between Earth and the moon. This produces a __________ tide, a tide with the ________ difference between consecutive low and high _______. These occur ________ a month.