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。

请数学老师解答 谢谢

请数学老师解答，谢谢

请数学老师解答 谢谢

请数学老师解答 谢谢

一家餐厅有A B两个list的side dishes，两个list都不重样，给出一共有18种搭配方式，问B list里有几个菜 条件1：AB一共有11个菜 条件2：A有2个菜 请数学老师解答 谢谢老师

一个圆内接长方形，问长方形周长是多少？ 条件1：圆半径为2； 条件2：长方形的一条边是2 请数学老师讲解，谢谢老师

请问下金老师，先通过主谓一致排除a，通过in doing sth “在哪方面干什么”意思不对排除ce，剩下bd怎么选择呢？感觉时态没法做选择，前面一个用using 一个用by the use of …使用过动词优于名词来最后选择b吗？

想请问Tina老师，这个题通过后面画线部分比较选项可以排出ad，cwith结构修饰主句主谓关系不恰当排除c，同位语be中summarize前面那群borrowers更好，但是be比较，我觉得e更好，因为that感觉又是引导一个如records这个名词的同位语解释说明什么样的一个热cords，但是答案选b，该怎么权衡呢？

请老师完整解答一下这道题解题思路，我选的A，认为后面是一个介词短语修饰语。

王文静老师你好，就这道题目，我特地查了字典，with可以表示一件事情的factor和这件事情的关系的，换句话说，C选项我读到with，我第一反应就是自动就理解为后面的两个条件（factor）是导致output tripled的原因，所以认为这句话即处理了因果关系也表达了两个factor之前的并列关系。麻烦老师指出我的语法理解问题