Some historians say that the most important contribution of Dwight Eisenhower's presidency (总统任期) in the 1950s was the U. S. interstate highway system. It was a【C1】______ project, easily surpassing the scale of such previous human【C2】______ as the Panama Canal. Eisenhower's interstate highways【C3】______ the nation together in new ways and【C4】______ major economic growth by making commerce less【C5】______ Today, an information superhighway has been built—an electronic network that【C6】______ libraries, corporations, government agencies and【C7】______ . This electronic superhighway is called the Internet,【C8】______ it is the backbone (主干) of the World Wide Web. The Internet had its【C9】______ in a 1969 U. S. Defense Department computer network called ARPAnet, which【C10】______ Advanced Research Projects Agency Network. The Pentagon built the network for military contractors and universities doing military research to【C11】______ information. In 1983 the National Science Foundation (NSF) ,【C12】______ mission is to promote science, took over. This new NSF network【C13】______ more and more institutional users, many of【C14】______ had their own internal networks. For example, most universities that【C15】______ the NSF network had intra-campus computer networks. The NSF network【C16】______ became a connector for thousands of other networks.【C17】______ a backbone system that interconnects networks, Internet was a name that fit. So we can see that the Internet is the wired infrastructure (基础设施) on which web【C18】______ move. It began as a military communication system, which expanded into a government-funded【C19】______ research network. Today, the Internet is a user-financed system tying institutions of many sorts together【C20】______ an " information superhighway".