10非充要条件

19. In concluding that DR must hire Ad Lib in order to ensure similar success throughout the country, the manager assumes that Ad Lib’s services are both necessary and sufficient for this purpose. Yet the manager has not provided any evidence to substantiate either assumption. Lacking such evidence, it is just as likely that some other ad agency would be equally or more effective. Even if Ad Lib’s services are necessary to achieve the manager’s goal, it is entirely possible that Ad Lib’s services would not suffice to ensure similar success elsewhere—due to the sort of factors mentioned above that might have contributed to the Megalopolis success but would not come into play in other cities. 192. Although a merger might be necessary to eliminate current confusion about which authority to contact for services, the editorial overlooks the possibility that the merger will not in itself suffice to eliminate this confusion. Specifically, until the residents of both communities are apprised of the change and learn how to respond appropriately, confusion will continue—and perhaps even increase in the short term. Thus, some measure of community awareness and responsiveness might also be required for the elimination of confusion.