24.  tides-the regular change in the level of Earth’s oceans.

25. flood tide-the incoming, or rising tide

26. ebb tide-outgoing, or falling tide

27. Moon’s gravity causes most tides.

28. changing tides happen about every 6 hours and  12 minutes.

29. there are about 4 tides every 24 hours and 50 minutes, two high tides and two low tides.

30. Spring tide is an extra high and extra low tide caused by the alignment of the Moon and the Sun.

31. Full Moon and New Moon cause the Spring tides.

32.  Neap tide is smaller tidal change than normal caused by the Moon and Sun being at a 90 degree angle, a right angle.

33. 1st quarter Moon and 3rd quarter Moon cause Neap tides.

34. intertidal zone-the land that is exposed (the beach) during low tide but is covered during high tide.