Can you please explain nature​

The graph shows a demand curve. which most likely accounts for the changes shown on the demand curve?

Mr. mann's science students were experimenting with speed. they set up a 1 meter (100 cm) track. the students used balls instead of cars. the balls were different sizes and made of different materials. four at a time, students rolled balls around the track to see which had the fastest and slowest speeds. some of their data are shown in the table. which ball will take the longest to complete one lap around the track?

97 points what types of changes have been made in the united states to protect people from earthquakes? a. communities are no longer located along fault lines. b. building codes ensure that structures can withstand shaking. c. warnings go off when an earthquake is expected, and people evacuate the area. d. barriers have been built to prevent flooding by a tsunami.