Ron：you can't just make random words parallel. parallelism is restricted to words that actually represent PARALLEL CONCEPTS in the sentence.

the two MAIN VERBS in the sentence are "call" and "attract". THOSE two verbs should be parallel.
"using" is a MODIFIER that modifies the "call" clause. this is as it should be, since "using" is a subordinate idea (it just describes the way in which the calling is done - it's not another action parallel to the calling).

so "call" and "attract" SHOULD be parallel; these two verbs should NOT be parallel to "using".

C错误在于picture内容是ocean current的pattern和cause而不是ocean current、pattern、cause三者一起，三者性质不同，不能并列。

A so as用法错误

Thai village crafts, as with other cultures, have developed through the principle that form follows function and incorporate readily available materials fashioned using traditional skills.

这句话的主句crafts have developed ... and incorporate... 一个是完成时态，一个是一般现在时，为什么说B选项要用have done呢？那后面的一般现在时不用管了吗？

Clearly price promotions are generally run at a loss, otherwise there would be more of them.
evidence for price promotions' "effect on the bottom line" ：价格促销影响bottom line的证据：如果不是occur in loss, 价格促销会更多

D：有left stroke就一定会有语言损害

像这种有交集的CR题，可以考虑画图法做：
1. Asthma is less common, 所以Asthma是小圆
2. Hay fever is more common，所以是大圆
3. 一个小圆和一个大圆交叉，交叉面积占小圆的95%，那么交叉面积占大圆肯定小于大圆的95%
D推不出来

E错在后半句：需要被更改的是文中的strategy，而不是BD2所描述的situation
C：the second is a judgment providing a basis for the argument's advocacy of a particular strategy. 该advocacy可以是正向的，也可以是负向的

in (b) and (d), the pronoun "its" is completely stranded; there's no antecedent for it anywhere.
takeaway:
if a sentence contains a COMPOUND NOUN (X and Y), you CANNOT use a pronoun to refer to just X or just Y, unless you use "the former" or "the latter" to make the distinction explicit.

* see #109 in the yellow og11. in that problem, all four of the incorrect answers try to use the singular pronoun "his" to refer to 1/2 of a compound noun. that's forbidden.
DO NOT post additional details of that problem here.

* this rule still holds even if X and Y take separate pronouns.
for instance:
joe and jane both have prestigious jobs, although her salary is much higher
would still be disallowed under the strict rules generally endorsed by the gmat, even though "her" can only refer to jane (since joe is male).
in this case, you'd just have to substitute "jane's" for "her".
that's the way it goes.

in (d), it's technically incorrect to use "they" because there is no place in which both systems are mentioned at once (e.g., with "and").

In D "or rapidly spinning collapsed star" is not a modifier, correct? Therefore does not refer to the "first pulsar" Right?

Ron：you know, i don't really know how you would classify that construction. it probably doesn't count as a modifier, because it doesn't actually modify the noun -- i.e., it doesn't expand upon, restrict, or change the meaning of the noun in any way, as modifiers do.

in any case, regardless of how you may or may not choose to classify it, you should know what this sort of construction (comma + OR + words) does: basically, it provides a definition of the word that comes before it.
e.g.
an own-goal, or goal accidentally scored in one's own net and counting towards the other team's score, is possibly the most embarrassing feat that a soccer player can accomplish.
here, the words following "or" (goal accidentally ... score) are the definition of the term "own-goal".
--
disclaimer:
the above usage is definitely not the only use of "comma + OR"; a much more common use for that construction is as a conventional conjunction, connecting two parallel structures. however, you should know this less common construction, so that you don't immediately mark it as wrong upon seeing it.

'to be sighted' is better for at least two reasons.

(1) 'first NOUN to be VERBed' is generally the preferred form in discussing the results of human efforts/actions/interference/perception/etc., while 'first VERBed NOUN' is generally used to indicate inherent qualities of the noun.
for instance, the following sentence is preferred:
henry bishop was the first musician to be knighted by a british monarch. --> knighting is performed by humans
the following is NOT preferred:
henry bishop was the first knighted musician in britain. --> this makes it seem as though being 'knighted' is an inherent quality with which henry bishop was born, or that he acquired it naturally/accidentally in some other way

(2) the word 'sighted' means 'having the sense of sight', so this sentence also contains the amusing alternative interpretation of referring to a pulsar that can actually see

Choice e：first of all, the word 'discovery' is missing. that's a crucial shift in meaning: it's the discovery, not the pulsar itself, that was 'announced'.
also, the word 'while' - which is sometimes used to indicate contrast - creates a strange ambiguity here: on first reading, it appears to suggest that the announcement (which took place in '68) happened during the summer of '67; this is the usual sense of 'while' occurring in this place in a sentence. (normally, if used to mark contrast, 'while' appears in front of a sentence.)

if 'while' is used for contrast, then it indicates that contrast IN ADDITION TO simultaneity. it's specifically used to describe two contrasting things that are simultaneously true.

yes that's awfully specific, but we can afford that kind of specificity because there are plenty of other contrast transitions (whereas, but, although, even though, yet, etc.) to describe situations that don't fit the 'simultaneity' criterion.

There are 2 problems with A.
- Major problem is "THE other infections." THE is too definitive here, carrying the connotation of "every single one of the other infections."
* THE is also incompatible with "such as":
- Correct: I never read this book, but I read the other books on the shelf.
- Correct: I never read this book, but I read other books on the shelf, such as "Right Hand, Left Hand" and "The Rise and Fall of the Third Reich."
- Incorrect: I never read this book, but I read the other books on the shelf, such as "Right Hand, Left Hand" and "The Rise and Fall of the Third Reich."
- Minor problem is "what they had not..." vs. "something they had not..." The "what" construction is awfully strong, suggesting that this was THE ONE THING they hadn't thought possible.
* As an analogy, compare the meanings of "I want to do what I love for a living" and "I want to do something I love for a living." The first suggests that the speaker has one particular field in mind; the second doesn't.

D：ability只能接to do!
E: an ability 是“dolphins are capable of recognizing themselves in mirrors”的概括性同位语

语义！B选项用that划分出语义层次，不是conducted operations，have greatly downsized，shut down altogether这三项平行，而是have greatly downsized，shut down altogether这两项平行，用that从句划分出去conducted operations

(b) is the best choice here.

(a) is vague because it's overly indirect: the meaning of "investigate changes ... as to their effects" is unclear. what's more, it's probably considered unidiomatic as well, at least in this sort of context.

(b) = correct
the participle "investigating" follows "experiments" immediately. no filler words are necessary; this is good concision.
the wording is clear; there are no awkward double possessives, etc., as in some of the other choices.
"would" is used properly here, as a past-tense form of "will". (i.e., if this sentence were translated into the present tense, it would read "...that changes ... will have")

(c) is ridiculously wordy; there's no way you should give this choice any serious consideration. if you don't realize pretty quickly that this choice is wrong, you should go back and read through a bunch of correct OG answers, trying to internalize the sights and sounds (the "vibe") of the correct answers.

(d) "changes in working conditions' effects" is at best awkward and vague, and at worst ambiguous: the intended meaning is the effects of the changes, but this sentence seems to indicated the effects of the conditions themselves. in other words, a literal reading of this sentence seems to indicate that the conditions themselves haven't changed - only their effects have. that's not the intended meaning of the original.

(e) "what the effects" is ungrammatical.
also, in constructions of this sort, "what" is generally redundant / unnecessary; it's better merely to say "to investigate X" rather than to say "to investigate what X is" (or other such wordy construction).

allay 减缓

1、需要用the xxx结构 只剩下ACE
2、C resulting from 不对 因为result主语不应该是The cottontail rabbit，而是这整件事情
3、本身有专门的名词形式的比动名词更好，the removal 比the removing好。

m.

中心词是have?

第5集看不了，有解决办法吗？谢谢