ron 的解释：
"Up" is redundant, since "until" already carries this meaning.

• The sentence implies that the Inuit are no longer nomads.
If they were still nomads, the sentence wouldn't say "until recently"; it would say "until now" (or some equivalent). Remember that "recently", albeit not too long ago, is still a time in the past.
So, you need the past tense.


选项D：本选项具有较高的迷惑性。利用图形背景原则，我们需要对比主句和伴随状语在时间轴上的持续时间。在逻辑上，“Inuit人住在igloos中”这个事件的持续时间肯定长于“Inuit人引领了流浪生活的风潮”的持续时间。这是因为，肯定是Inuit人“先”住在igloos中，然后他们才能引领流浪风潮。因此，shelter应该是从属成分（伴随状语），lead是主句。

in addition to只能在身后接名词或名词短语
在逻辑上，例句发生时，我们并不知道什么时候能“确定这个时间”，甚至不知道是否能确定，因此，determine how and when mammals colonized the islands of the West Indies这个事件在本句中没有时间的终止点，只能用ing短语来表达。
C选项：不定式短语to determine应改为介词短语determining，这点考查了不定式和ing的区别。用之于本题，给“确定繁殖时间”提供线索，不代表我们真的能确定繁殖的时间，也不代表说话者在主观上认为这个事件“会”发生（只提供了线索，哪怕这个线索是重要的，也不代表我们很快就能确定哺乳动物的繁殖时间了）。因此，应该用ing短语来表达。
C. did应该为did so (曼哈顿讲的)
D选项：省略有误。省略的原则是，在不引起歧义的情况下，一样部分均应该省略。在本选项中，除了连词when和how的不同，其余部分两句均是相同的，所以they和were均应该省掉。

这个题和之前一道题很像，都是sth provide sth(support&clues) for doing(determing&classify) sth.主语是东西不是人，所以不能用to do 表示目的，只能用doing 表示用途。

我觉得这道题考的是平均数谬误。

考了好多逻辑语义的题目

可以画一个2*2的表格
https://www.beatthegmat.com/gmatprep-lima-beans-and-brussels-sprouts-t18453.html

at speeds（that will be）much higher than （speeds that）are currently possible

Neither compares tasks in dissimilar jobs (that is, jobs across occupational categories) in an effort to determine whether or not what is necessary to perform these tasks can be quantified in terms of its dollar value to the employer.

Bi, can you stop justifying your ignorance?
According to the context , we can hardly assume the very intention of human being is to encounter more prey, nor should we justify the usage of "HAD done" .
In case of any refutation, here is the origin.
The research, which was published in the Feb. 9 issue of the journal Science, has implications both for the modern-day debate over reintroduction programs and for a historical debate over what happened 10,000 to 50,000 years ago, when one particular predator, humans, expanded its territory and encountered large numbers of native prey. Some experts think that a ''blitzkrieg'' of killing by advancing humans contributed to the extinctions of many large animals in that era.

See, It's an article from NY Times. what I wanna say is stop offering your misguidance and misinterpretation!

Ron:
C:the major problem with (d) is the incorrect construction "of + NOUN + VERBing".
also, it's unidiomatic to say that a RATE is "half" (or "more/less than half"). you could say that a rate is 50%, but not "half".

只看最后一个句子就好了，裂开。。。

A错在哪里啦？

A is employed as B的意思是：A被雇佣为B-积极正面
A is employed to be B的意思是：A被利用为B-消极负面
幸好现在遇到了，要是未来工作中用错了就尴尬了

错选b的我。。。。哎 https://forum.chasedream.com/thread-348240-1-1.html ability to do！ability to do！

A,B，without adequate amounts of sleep 逻辑主语应该是people，如果主句的主语改成people有没有问题？
C, they ... people's skills... 指代不对
E，adequate本来就有amount they need的意思，足够多的

审题！x和y是正整数

rather than by burning calories to generate it
by drawing 与by burning平行

应该只根据前面部分来选

哥，这不是加强，是找assumption! 另外题目翻译也错了！！！是另外一个group, to who was described this scenario.

行文逻辑：结论-条件-确认结论
BF1:碎片本身不含硫，但大气层下的云层含硫
BF2:碎片的大小至少要使它不被烧焦在大气层中

条件一：把w+y看成是一个负数为a, 把x+y看成是另一个负数为b, a-b=w-y，试想一下，两个负数相减，我们不能并不能判断是大于零还是小于零，也就无法得出w和y的大小了。（我觉得这样理解比较清楚）
条件二：就很明显了，直接给出y和w的关系