Read the excerpt from The Evolution of Useful Things. But since it is 3M's policy (and that of other enlightened companies) to allow its engineers to spend a certain percentage of their work time on projects of their own choosing, a practice known as "bootlegging," Fry was able to gain access to the necessary machinery and materials and to spend nearly a year and a half experimenting and refining his idea for sticky – but not-too-sticky – slips of paper that could be used for "temporarily permanent" bookmarks and notes. Which statement best describes the relationship of ideas in this text? A cause-and-effect relationship is signaled by the words "But since." A cause-and-effect relationship is signaled by the words "their own choosing." The passage of time is signaled by the words "of their work time." The passage of time is signaled by the words "a practice."