单选题 The extent of a nation's power over its coastal ecosystems and the natural resources in its coastal waters has been defined by two international law doctrines: freedom of the seas and adjacent state sovereignty. Until the mid-twentieth century, most nation favored application of broad open-seas freedoms and limited sovereign rights over coastal waters. A nation had the right to include within its territorial dominion only a very narrow band of coastal waters (generally extending three miles from the shoreline), within which it had the authority, but not the responsibility to regulate all activities. But, because this area of territorial dominion was limited, most nations did not establish rules for management or protection of their territorial.
Regardless of whether or not nations enforced regulations in their territorial waters, large ocean areas remained free of controls or restrictions. The citizens of all nations had the right to use these unrestricted ocean areas for any innocent purpose, including navigation and fishing. Except for controls over its own citizens, no nation had the responsibility to control such activities in international waters. And, since there were few standards of conduct that applied on the: "open seas", there were few jurisdictional conflicts between nations.
The lack of standards is traceable to popular perceptions held before the middle of this century. By and large, marine pollution was not perceived as a significant problem, in part because the adverse effect of coastal activities on ocean ecosystems was not widely recognized, and pollution caused by human activities was generally believed to be limited to that caused by navigation. Moreover, the freedom to fish, or over fish, was an essential element of the traditional legal doctrine of freedom of the seas that no maritime country wished to see limited. And finally, the technology that later allowed exploitation of other ocean resources, such as oil, did not yet exit.
To date, controlling pollution and regulating ocean resources have still not been comprehensively addressed by law. But two recent developments may actually lead to future international rules providing for ecosystem management. First, the establishment of extensive fishery zones, extending territorial authority as far as 200 miles out from a country's coast, has provided the opportunity for nations individually to manage larger ecosystems. This opportunity, combined with national sell-interest in maintaining fish populations, could lead nations to reevaluate policies for management of their fisheries and to address the problem of pollution in territorial waters. Second, the international community is beginning to understand the importance of preserving the resources and ecology of international waters and to show signs of accepting responsibility for doing so. Thus it will become more likely that international standards and policies for broader regulation of human activities that affect ocean ecosystems will be adopted and implemented.

单选题 Until the mid-twentieth century there were few jurisdictional disputes over international waters because______.

单选题 The author suggests in the third paragraph that, before the mid-twentieth century, mat nations' actions indicated that______.

单选题 Before the mid-twentieth century, nations failed to establish rules protecting their territorial waters because______.

单选题 From the last paragraph we learn that the extension of fishery zones may be a good thing in that ______.

单选题 The passage as a whole can best be described as ______.