All the waves that are around us have similar properties. One type of wave is a (4)__ wave, which moves perpendicular to the
direction of the wave. Each wave has a specific (5) or a
measured distance from one point to the same point on the wave.
This property is usually measured from one (6) to the other,
or from the highest point to the next highest point. It could also be
measured from one lowest point, or (7)_, to the next lowest
point. If you want to know how high the wave is, you should
measure the (8) from the rest position to the crest
or to the trough.