Figure 2: Generalized record of the magnetic polarity reversals near the mid-ocean ridge in the Pacific, South Atlantic, and North Atlantic oceans. Periods of normal polarity are shown in color and correspond to those illustrated in Figure 1. 1. Use Figure 1 to identify and mark the periods of normal polarity with the letters a-f on each mid-ocean ridge in Figure 2. (Note: The left side of the South Atlantic has already been done and can act as a guide. The periods of normal polarity through care illustrated in the Pacific basin.) 2. Using the South Atlantic as an example, label the beginning of the normal polarity period c, "2 million years ago," on the left sides of the Pacific and North Atlantic diagrams. 3. The (Pacific, South Atlantic, North Atlantic) has spread the greatest distance during the last 2 million years