Some surfaces have experienced more recent geological activity (like volcanism or erosion) that wiped out previously existing craters. They are referred to as "geologically younger" than surfaces that have not experienced activity. We can therefore use crater counts to determine the "age" of a surface, approximating how long ago the last geological event occurred in that area. Using this technique (and assuming these pictures are representative of the crater density on the entire planet), rank the planets in order of their geological age, from oldest to youngest.

Astudent conducts an experiment to see how music affects plant growth. the student obtains four identical plants. each one is potted in the same type of soil and receives the same amount of sunlight and water each day. plant a listens to classical music for three hours each day. plant b listens to rock music for three hours each day. plant c listens to country music for three hours each day. plant d does not listen to any music at all. 2. based on the experiment in the scenario, which visual aid would be most in showing the change in the plants' heights over time? a. a pie chart b. a line graph c. a timeline d. a bar graph