这题的主旨题，我怎么都理解不了，请牛牛指教！

elsachialee

Maps made by non-Native Americans to depict Native American land tenure, resources, and population distributions appeared almost as early as Europeans' first encounters with Native Americans and took many forms:  missionaries' field sketches, explorers' drawings, and surveyors' maps, as well as maps rendered in connection with treaties involving land transfers. Most existing maps of Native American lands are reconstructions that are based largely on archaeology, oral reports, and evidence gathered from observers' accounts in letters, diaries, and official reports; accordingly, the accuracy of these maps is especially dependent on the mapmakers' own interpretive abilities.

Many existing maps also reflect the 150-year role of the Bureau of Indian Affairs (BIA) in administering tribal lands. Though these maps incorporate some information gleaned directly from Native Americans, rarely has Native American cartography contributed to this official record, which has been compiled, surveyed, and authenticated by non-Native Americans.  Thus our current cartographic record relating to Native American tribes and their migrations and cultural features, as well as territoriality and contemporary trust lands, reflects the origins of the data, the mixed purposes for which the maps have been prepared, and changes both in United States government policy and in non-Native Americans' attitudes toward an understanding of Native Americans.

Question #45.

The passage mentions each of the following as a factor affecting current maps of Native American lands EXCEPT

(A) United States government policy
(B) non-Native Americans' perspectives on Native Americans
(C) origins of the information utilized to produce the maps
(D) changes in the ways that tribal lands are used
(E) the reasons for producing the maps

Question #46.  

The passage suggests which of the following about most existing maps of Native American lands?

(A) They do not record the migrations of Native American tribes.
(B) They have been preserved primarily because of their connection with treaties involving land transfers.
(C) They tend to reflect archaeological evidence that has become outdated.
(D) They tend to be less accurate when they are based on oral reports than when they are based on written documents.
(E) They are not based primarily on the mapmakers' firsthand observations of Native American lands.

Question #47.

Which of the following best describes the content of the passage?

(A) A chronology of the development of different methods for mapping Native American lands
(B) A discussion of how the mapmaking techniques of Native Americans differed from those of Europeans
(C) An argument concerning the present-day uses to which historical maps of Native American lands are put
(D) An argument concerning the nature of information contained in maps of Native American lands
(E) A proposal for improving the accuracy of maps of Native American lands

yorku

看了两遍文章总算明白一点：

理解的关键我觉得而是最后一大句： Thus our current cartographic record relating to Native American tribes and their migrations and cultural features, as well as territoriality and contemporary trust lands, reflects the origins of the data, the mixed purposes for which the maps have been prepared, and changes both in United States government policy and in non-Native Americans' attitudes toward an understanding of Native Americans.

作者通过前面列举之前的制图者制图的一些形式方法，说明之前的地图可以反应的东西。因为吸取前人的经验，我们现在去制图就要结合Native American tribes and their migrations and cultural features, as well as territoriality and contemporary trust land，去反应一些新的东西，比如政策的转变，制图的目的等等。

A的中心词是method，C-use E-accuracy 都不是文章的中心词。文章不是讨论制图方法，使用或者地图的精准性。而是讨论的在制作地图的过程中反应出了什么的时代信息。

其实我也是小白...so，大家继续讨论吧....

rmbaos

同问。不明白为什么是nature information???