花了30分钟才弄明的阅读，OG12-103

pterosaur

问题提出了 the discovery of gold deposites 所以还是定位在第三段。Methods widely used today include analysis of aerial images
that yield a broad geological overview; geophysical
techniques that provide data on the magnetic,
electrical, and mineralogical properties of the
rocks being investigated; and sensitive chemical
tests that are able to detect the subtle chemical
halos that often envelop mineralization.
从中可以看出为了找矿，用了很多高科技的方法。所以选择B。

pterosaur

112. It can be inferred from the passage that which of the
following is easiest to detect?
(A) A gold-quartz vein system originating in
magmatic fluids
(B) A gold-quartz vein system originating in
metamorphic fluids
(C) A gold deposit that is mixed with granite
(D) A gold deposit that has shed alluvial gold
(E) A gold deposit that exhibits chemical halos

pterosaur

什么是最简单的能找到的mines？第二段描述了过去找金的过程。Most of the gold deposits discovered during the original gold rushes were
exposed at the Earth’s surface and were found
because they had shed trails of alluvial gold
that were easily traced by simple prospecting
methods.大家看到其中的easily了吗？所以选择D。 这道题我选择了B，真是太不小心了！悲剧。

pterosaur

113. The theory mentioned in lines 1–5 relates to the
conceptual models discussed in the passage in which
of the following ways?
(A) It may furnish a valid account of ore-forming
processes, and, hence, can support conceptual
models that have great practical significance.
(B) It suggests that certain geological formations,
long believed to be mineralized, are in fact
mineralized, thus confirming current conceptual
models.
(C) It suggests that there may not be enough
similarity across Archean-age gold-quartz vein
systems to warrant the formulation of
conceptual models.
(D) It corrects existing theories about the chemical
halos of gold deposits, and thus provides a basis
for correcting current conceptual models.
(E) It suggests that simple prospecting methods still
have a higher success rate in the discovery of
gold deposits than do more modern methods.

pterosaur

这道题定位conceptual models 在第三段的最后和第四段的开始，conceptual models, which take into account theoretical studies of relevant
factors. 可以看出模型是以理论研究为依据的。
These models are constructed primarily from
empirical observations of known mineral deposits
and from theories of ore-forming processes.
所以A。

pterosaur

114. According to the passage, methods of exploring for
gold that are widely used today are based on which of
the following facts?
(A) Most of the Earth’s remaining gold deposits are
still molten.
(B) Most of the Earth’s remaining gold deposits are
exposed at the surface.
(C) Most of the Earth’s remaining gold deposits are
buried and have no surface expression.
(D) Only one type of gold deposit warrants
exploration, since the other types of gold
deposits are found in regions difficult to reach.
(E) Only one type of gold deposit warrants
exploration, since the other types of gold
deposits are unlikely to yield concentrated
quantities of gold.

pterosaur

这道题做错了 也想了很久 其实很简单 关键是题目没有看清楚。现在大家为什么用这么多的理论/技术来找金矿，前提是什么？从文章中可以看出，在表面的矿藏都已经基本上被开采完了，现在要找那些藏在地底下的金矿了。这就是现在找金矿的前提，所以 C。
most of the Earth's remaining gold deposits are buried and have no surface expression.