一个坏的都没拿到和拿到一个坏的是互斥事件
从5个苹果里任意拿两个苹果，有10种拿法；
从4个好苹果里任意拿两个苹果，有6种拿法；
则一个坏苹果都没拿到（即两次都拿的好苹果）的概率是6/10,即3/5
其中有一个坏苹果的概率是1-3/5=2/5

（1）因为p是质数，大于2，所有从1到p+1之间最大的质数应该是p，就是第100个质数是p，从2，3，5……数到第100个质数就是p的值，唯一且可以确定
（2）两个数之间一共有多少个质数，这个数是固定值，p唯一且可以确定

每周5天，每天放一次

这个不是对应下面这句话吗？所以感觉d也是对的呀。难道也要就近？？而且文中没有提到rapid相关的，只提到数量，所以我觉得d更对的感觉。求解。causing millions of cubic kilometers of crustal debris to be ejected, denser material from the Moon's mantle rose up beneath the impactors almost Immediately, compensating for the ejected material and thus leaving no low gravity anomaly in the resulting basin

C中so指代前文的reported high marital satisfaction

請問～第八題的A選項這樣不算是違背前提了嗎？

"using", like "including", doesn't follow the normal rules for "__ing" modifiers.

when "using" is used in this kind of context (to describe the tools with which something is accomplished), its behavior is essentially identical to that of "with".
thus, you can think of this "using" as a preposition, like "with".

the problem with (c) is NOT grammatical; the grammar of (c) is just fine.
the problem with (c) is that it uses two different transitions incorrectly.

* if you say "subject + clause + BY VERBing", then "by VERBing" must explain HOW the main clause occurred.
e.g.
i prepared for the test by reviewing takeaways on the MGMAT forums.
note that the boldface clause describes HOW i prepared for the test.

choice (c) means that using websites, etc. was how the industry organized the campaign -- in other words, they used the websites and public meetings to organize the campaign in the first place. that's an incorrect meaning.
(the campaign ITSELF used these things; the correct modifier in (a) and (b) shows that relationship.)

* if you say "subject + clause + IN VERBing", then subject + clause must be an ACTUAL PART of the action of VERBing.
e.g.
i solved all the problems in OG12 in preparing for the GMAT.
--> notice that solving the problems IS ACTUALLY PART OF preparing for the test.

choice (c) fails here, too, since organizing the campaign (the main clause) is not ACTUALLY PART OF convincing the government.


choice (e) has two problems.

the first is "in convincing", which is wrong for the same reason why it's wrong in choice (c). see above.

the other is incorrect verb tense. "which used" (simple past tense) shouldn't be in a tense occurring prior to "has organized" (present perfect). this construction mistakenly suggests that the campaign "used X, Y, and Z" before it was even organized in the first place.

an "appositive" vs an "absolute phrase"

you should mostly use MEANING to differentiate between the two.
for instance:
the singer sang the song with intense emotion, her voice moving the audience to tears --> absolute phrase
this is the official guide, a book containing over 800 problems --> appositive

if you think in terms of meaning, it's a rather large difference: the absolute phrase modifies the ACTION of the preceding clause, while the appositive gives more information about a THING/ENTITY/CONCEPT.

it's so important to ascertain the meaning of the sentence FIRST, before you dive into analyzing possible errors.

the same thing is true for many other types of modifiers, such as prepositional phrases, as well.

e.g.
I read the book on the train --> this prepositional phrase modifies the ACTION "read the book".
I read the book on the table --> this prepositional phrase modifies the NOUN "book".
grammar won't help you figure this out -- you have to ascertain the meaning of the sentence using the same sort of common sense that allows you to have everyday conversations with people who don't speak using perfect grammar (i.e., everyone you will ever talk to).

modifier issues aren't really grammar issues -- they're meaning issues.
i.e., modifiers are not normally wrong because they are grammatically incorrect; they are normally wrong because they modify things that don't make sense. therefore, in most modifier errors, there is no such thing as a "proper grammar explanation" because grammar isn't even the issue in the first place.

in the construction "it is (adjective) for XXXX to (verb)", the adjective describes what XXXX experience(s) in trying to (verb).

e.g.,
This book is hard for me to read.
(I experience difficulty in reading this book.)

It is difficult for Liz to talk to her ex-husband.
(liz has trouble talking to her ex. we don't know whether the converse is true.)

so, choice E is saying that the appliances themselves have to spend a lot of money "to be bought on credit". well, that doesn't make any sense.

also，even if your knowledge of these constructions is nil, you should still be able to kill E because it's so terribly wordy and clunky, as compared to the other choices.
(no, wordiness is not an actual error... but the correct answers are NEVER more wordy / less efficient than the incorrect answers. thus, you can still use differences in wordiness as viable criteria for elimination.)

"so that" is not a modifier; it connects two independent sentences. so, the problem with using "the" here is that "the" would have to make sense BY ITSELF.

consider the following:
I have the box that you bought yesterday.
I have the box in which the sewing scissors are stored.
vs.
I bought a box, so that you can store your sewing scissors.
--> we CAN'T write "the" here, because "the box" doesn't make any sense by itself.

for the same reason, the choices with "the kind..." and "so that" don't work, either.

“Political situations have caused an increase in gas prices ” correct
“Political situations have caused increasing gas prices ” incorrect

You can't memorize this kind of thing as a structure, because structure isn't the issue. The issue is what the sentence means.

In the pair above, the incorrect example is wrong because political situations don't "cause gas prices"; that's nonsense. (Gas prices are not an event precipitated by political events.) In this instance, "increasing" is an adjective.

In the current sentence, the meaning is altogether different.
We're talking about the action of "buying on credit".

In addition, "buying" is the best noun available, because there's no dedicated noun form available (e.g., there's no such thing as, say, "buyage"). By contrast, the noun "increase" is available.

You can use "it is (adjective) for XXXX to (verb)" construction without a subject, but only if the statement is universally true -- i.e., for everyone who might find him-/herself in the situation.
E.g., when interest rates go up, it becomes more expensive for absolutely anyone to buy on credit, because ... well, because interest rates went up.

In a sentence describing a consequence that's particular to a certain person/group, you have to say who that is. Here, you're talking about consequences that pertain to a certain executive, so the sentence must be specific.

If the "to ___" phrase is long enough, this construction will become preferable.
For instance, in this sentence, change "buy(ing) on credit" to "buy(ing) expensive items on credit or borrow(ing) substantial sums of money".
With a phrase that long, choice B, while still technically correct, will become completely unreadable. With its agreement problem fixed, choice C will still work well.

either "by imitating and practicing" or "by imitation and practice" is acceptable, here. once you've established parallelism, the point is to move on to other criteria.

"from each one to others", "from one to another" and "to others"
this is a distraction.
if you see random changes in word choice -- and you can't decide them /1/ logically or /2/ by referring to something else in the sentence -- then those choices are there just to distract you. ignore them and find something else.

the sentence is written very specifically to emphasize the curiosity per se.
ironically, the sentence is written expressly to MINIMIZE the importance given to the chimpanzees themselves!

if the point was to emphasize the involvement of the chimps, then the sentence would be written with the chimps as the subject. this would be quite easy to do: ...they transmit patterns of behavior by imitating them...

instead the author has taken a sentence whose earlier subject is the chimps and has specifically changed the sentence (into a passive form) so that the chimps ARE NOT the subject anymore.
that's a pretty strong indication that the point is to de-emphasize the chimps, and to emphasize the cognitive process itself, as much as possible.

'so that' implies that chimpanzees are actually thinking, 'Hmm... if i exhibit curiosity, then i'll be able to catch on to my fellow chimps' behavior patterns. ...no！

just remember, your common sense will be integral in determining 'intended meaning' (since there are no rules for what is 'intended').

deny sb sth 双宾语
在gmat中 看大不看小 最重要的还是核心意思-谓语

more than three times as many 【independent institutions of higher education charge tuition and fees of under $8,000 a year 】as 【 ( independent institutions of higher education) charge over $16,000】.

先抓到结论会比较有帮助～

Conclusion: A recession in the future will not hurt teaching jobs at government-funded schools.