According to a theory advanced by researcher Paul Martin，the wave of species extinctions that occurred in North America about 11,000 years ago，at the end of the Pleistocene era，can be directly attributed to the arrival of humans，i.e.，the Paleoindians， who were ancestors of modern Native Americans. However，anthropologist Shepard Krech points out that large animal species vanished even in areas where there is no evidence to demonstrate that Paleoindians hunted them.Nor were extinctions confined to large animals： small animals，plants，and insects disappeared，presumably not all through human consumption. 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. Still，Krech attributes secondary if not primary responsibility for the extinctions to the Paleoindians，arguing that humans have produced local extinctions elsewhere.But，according to historian Richard White，even the attribution of secondary responsibility may not be supported by the evidence. 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；yet recent archaeological discoveries are providing evidence that the date of human arrival was much earlier than 11,000 years ago. 　3. In the last sentence of the passage， the author refers to “recent archaeological discoveries” (lines 27-30) most probably in order to 　　(A) Refute White's suggestion that neither Martin nor Krech adequately account for Paleoindians' contributions to the Pleistocene extinctions 　　(B) Cast doubt on the possibility that a more definitive theory regarding the causes of the Pleistocene extinctions may be forthcoming 　　(C) Suggest that Martin's， Krech's， and White's theories regarding the Pleistocene extinctions are all open to question 　　(D) Call attention to the most controversial aspect of all the current theories regarding the Pleistocene extinctions 　　(E) Provide support for White's questioning of both Martin's and Krech's positions regarding the role of Paleoindians in the Pleistocene extinctions 老师，我在做这道题的时候，首先定位到最后一句觉得没说什么重点，就有个yet转折，可能这是用来驳斥前面的某些观点的。所以看选项找有没有驳斥的意思的， 发现5个选项全都在驳斥。。。心里慌了往前找。再回去找的时候时间已到。我就随便选了个B（时间一到各种混乱），因为在做这篇文章之前，我大体看了下原文，记住了原文讲的是P反驳M，W反驳P。后来答案我也看明白了，我认为我做这道题的思路出现了偏差，我想问一下应该怎么修正。

In the last few years, the number of convicted criminals given community service ( sentences, which allow the criminals to remain unconfined while they perform specific jobs benefiting the public, have ) risen dramatically. Asentences, which allow the criminals to remain unconfined while they perform specific jobs benefiting the public, have Bsentences, performing specific jobs that benefit the public while being allowed to remain unconfined, have Csentences, performing specific jobs beneficial to the public while they are allowed to remain unconfined, have Dsentences which allow them to remain unconfined in their performing of specific jobs beneficial to the public has Esentences allowing them to remain unconfined while performing specific jobs that benefit the public has 答案是E，开始选的D，根据the number判断谓语是单数，只能用has，但是又感觉has是跟着which从句里的，导致整个句子没有谓语。一遍读下来很混乱，不知道想表达什么，也不知道该选什么了。麻烦老师讲解。

Even today, a century after Pasteur developed the first vaccine, rabies almost always kills （its victims unless inoculated） in the earliest stages of the disease. (A) its victims unless inoculated (B) its victims unless they are inoculated (C) its victims unless inoculation is done (D) the victims unless there is an inoculation (E) the victims unless inoculated 答案是B，错选了E。感觉逻辑好混乱，不知道B的its和they指代什么，麻烦老师讲解。

His studies of ice-polished rocks in his Alpine homeland, far outside the range of present-day glaciers, led Louis Agassiz in 1837 to propose the concept of an age ( in which great ice sheets had existed in now currently temperate areas. ) A in which great ice sheets had existed in now currently temperate areas B in which great ice sheets existed in what are now temperate areas C when great ice sheets existed where there were areas now temperate D when great ice sheets had existed in current temperate areas E when great ice sheets existed in areas now that are temperate 答案是D，错选了B。BD纠结，不知道该如何判断。第二遍做这道题还是把握不好句意，麻烦老师讲解。

The company is negotiating to sell its profitable credit card ( subsidiary, which it plans to use money from ) to acquire some of the mortgage-servicing operations that are being sold by troubled savings institutions. (A) subsidiary, which it plans to use money from (B) subsidiary, from which it plans to use money (C) subsidiary, and it plans the use of money from that (D) subsidiary and plans to use money from that sale (E) subsidiary and plans the use of money from that sale 答案是D，错选了B。上来就把CDE排除了，因为and前后时态不一致，而且C的it多余。AB比较，which和from which指代的感觉都不是很清晰，然后根据A结尾的from 和原文的to连接起来太别扭，就把A排除了，麻烦老师讲解。

( Based on the growth rates of large modern reptiles such as ) the Galapagos tortoise and examination of fossils of juvenile dinosaurs, scientists estimate that the larger dinosaurs probably lived to be between 100 and 200 years old. A. Based on the growth rates of large modern reptiles such as B. On the basis of growth rates of large modern reptiles such as C. Based on the growth rates of large modern reptiles like D. On the basis of growth rates of large modern reptiles, like those of E. Based on the growth rates as those of large modern reptiles like 答案是B，错选了A。科学家基于爬行动物的生长率，估计了恐龙的存活时间。科学家做based on的逻辑主语有错吗？麻烦老师讲解。 (Based on account of various ancient writers) , scholars have painted a sketchy picture of the activities of an all-female cult that, perhaps as early as the sixth century B.C, worshipped a godness known in Latin as Bona Dea "the good goddess". A. Based on account of various ancient writers B. Basing it on various ancient writer's accounts C. With accounts of various ancient writers used for a basis D. By the accounts of various ancient writers they used E. Using accounts of various ancient writers 答案是E，还是错选了A。做题时在AE纠结了好久，因为不确定学者作为“基于不同作家的解释”的主语是不是错的，而且感觉基于要比使用的表达更好，尽管可以确定using的主语是学者，但还是把E排除了，麻烦老师讲解。 因为不知道这两道题是犯了什么错误，所以去有道查了based on 的例句，发现人是可以做主语的：Based on the finding, one might predict that the bank should increase its display and budget. 以及 Based on that representation, the district judge denied a motion to dismiss the new comlaint. 麻烦老师讲解这几个题的区别。

麻烦老师讲一下

老师，没看懂题目，麻烦讲解一下。

老师，这个题设两个都喜欢的人数＝两个都不喜欢的人数为x，那喜欢a的就是4x,喜欢b的也是4x。总人数就等于x+4x+4x-x吗

老师，麻烦讲解一下。

老师，麻烦讲解一下。