1. When rewinding an audio or videotape, one reel winds fastest at the end. Which reel is this, and why
does it speed up?

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.