How did ancient chinese kings maintain control of there dynasty

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?

Which of the following would a historian most likely study to find data

Which of the fallowing sports became spectator sport at the turn of the century ? a)basketball and boxing b)soccer and football c)racquetball and badminton d)polo and swimming