In the last sentence of the passage, the author refers to "recent archaeological discoveries" most probably in order to?
White发现Martin的thesis取决于人类到来的时间与大型动物的灭绝的时间相同，而Krech虽然意识到了时间有争议，但他并没有提出异议。但最近的考古研究证明人类到来的时间其实早了11000年。因此说明人类到来与灭绝没有直接关系。因此反对Martin和Krech，也就是支持了White。

Which of the following, if true, would most weaken Krech's objections to Martin's theory?
C的问题是，选项想用“同因反果”来削弱K的观点，即，P era有climatic change, 有灭绝，其他era也有climatic change, 但是却没有灭绝，所以climatic change不是导致灭绝的原因。但是选项中并没有提到其他era没有灭绝这件事，这是我们自己脑补的事实，即选项中并没有提供“果”，所以错
有关B的argument是：“Nor were extinctions confined to large animals: small animals, plants, and insects disappeared, presumably not all through human consumption.”意思是说，不光大动物灭绝了，小动物和植物昆虫也灭绝了，不可能人类还consume小动物啥的吧（所以不可能是human consumption导致大动物灭绝）。所以B说人类确实use了这些小动物，就是一个很直接的削弱。

错误定位到White observes that Martin's thesis depends on coinciding dates for the arrival of humans and the decline of large animal species, and Krech, though aware that the dates are controversial, does not challenge them.这里M并没有提出对日期的争论!
正确定位Krech also contradicts Martin's exclusion of climatic change as an explanation by asserting that widespread climatic change did indeed occur at the end of the Pleistocene.
这句话没理解,意思是K反驳了M把气候变化排除掉.

D. 是这些norms受到了mercantilist notions的支持，而不是norms帮助贯彻了mercantilist notions，故错误

原文：Clearly price promotions are generally run at a loss, otherwise there would be more of them.
所以 没有经常举办这个活动的原因是因为run at a loss即亏本，没有利润
问题问价格促销对于利润的影响（即没有利润）的证据是什么，就是因为没有经常举办这个活动呀，没有经常举办这个活动就是它亏本的证据

A.他们证实了研究人员对地幔内部对流可以垂直抬升或降低地球表面的理论的怀疑。
D.他们已经让以前持怀疑态度的研究人员相信，非洲南部地下地幔深处的岩层可能创造了superwell.
没注意问题里面的细节词语!!不是confirm doubt.
做CR也经常错这个

定位点在However, recent technological advances have allowed geophysicists to make three-dimensional "snapshots" of the mantle by measuring vibrations, or seismic waves, set in motion by earthquakes originating in the planet's outer shell and recording the time it takes for them to travel from an earthquake's epicenter to a particular recording station at the surface. Because geophysicists know that seismic waves become sluggish in hot, low-density rock, and speed up in colder, denser regions, they can now infer the temperatures and den- sities in a given segment of the interior.我看成后面一句话了.

have greatly downsized复数，表明主语是companies而不是B company。

tech = plant varieties + chemical
文章后半段分为：
1. 教育程度 ⬆️ => plant ⬆️ chemical ⬇️
2. 市场连接 ⬆️ => both ⬆️
3. 可用未开垦土地 ⬆️ => both ⬇️
4. kinship ⬆️ => plant ⬆️ chemical ⬇️
在不用想太复杂的情况下，看完题干就会想到是两个都⬇️的情况，就是D了

🐎：
文中只有一处出现了1997年之前24年间GDP在增长这句话，“One point these journalists overlooked is that in 1997, as in the twenty-four years immediately preceding it, the real GDP per capita grew nearly one-half percent a year more slowly than it had on average between 1873 and 1973. ”就说了24年间的比1873-1973年间的more slowly，slowly的原因没有介绍，后面说的都是1997年与1873-1973年的对比了，没有再提过这24年。
在1997年，正如之前的24年一样，实际的人均GDP增长速度比起在1873-1973年之间的增长速度放缓了0.5%。-> 只给出了增长放缓的事实，没有阐述背后的原因

E then多余，过去分词已经表示了when引导状语从句一样的时间概念；they和their完全指代single locusts，不优

简单来说，过程是这样的，有两种情况：
1，在同一个岛上进化，然后分开，这样他们会发展呈different spcies， 但是closely related。
2，在不同的岛上单独分开进化，这样的结果是，在一个岛上的anoles更加closely related to 同一个岛上的其他种类的anoles，而不是不同岛上的相同anoles。

主要目的是≠文章都讲了什么
We can eliminate (C) because the author didn't write the passage to outline major questions. If this were true, we'd see more of an outline-like breakdown of more than one question. Instead, we have a deep dive into a single question ("How do these two groups define behavioral?") and a single example (Shaker) used to address that question.

B选项，文章第一段话“These communities\' agricultural systems-which were \"intensive\" in the use of labor rather than \"extensive\" in area-may have given rise to polit- ical leadership that managed both labor and food resources. ”说明了这是个intensive agricultural systems，因此后面的内容都和extensive无关

E选项，meal tax和sales tax

D. the digging 被当作是an epic, 但 family legends不知道是指digging还是epic
E. 按照它字面想表达的意思理解: family legends 被当作是an epic (许多的传奇故事可以被看作是一卷史诗, 单复数没问题), 其中一个family legends是the digging. 这样理解毫无歧义. ok

legends被人们当作an epic，其中一个legends是the digging...

a billion dollars over what was predicted / had been predicted just two months ago.
a billon dollars more than they had predicted just two months ago.

语法点：than引导从句。这个网址解释得比较好https://toefl.langlib.com/reading/article/381407901。

A选项错误原因：文章第二段只讲了Raccoons and striped skunks很少在upland habitats，也就是songbird nests所在的地方，但是不能以此推断出所有的most waterfowl-nest predators就不能到，不能用特殊推出一般

A选项错误原因：文章第二段只讲了Raccoons and striped skunks很少在upland habitats，也就是songbird nests所在的地方，但是不能以此推断出所有的most waterfowl-nest predators就不能到，不能用特殊推出一般