The African Maasai have adopted the Living Wall project in their bid

Official explanation
Meaning Analysis
• The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators;
• the natural fences built of myrrh trees have been designed to prevent the attacks,
• and they do.
The sentence talks about the African Maasai who have taken up the Living Wall Project. They have taken up this project in an attempt to save their livestock from predators’ attacks. The next part of the sentence elaborates on the Living Wall Project. These Maasai build natural fences of the myrrh tree. These fences have been designed to prevent the predators’ attacks and are successful in preventing them.

Error Analysis
• Since all the actions pertain to the present context, all the tenses have been correctly used.
o The use of the present perfect tense verb “have adopted” is correct because this action started sometime in the past and is still taking place.
o The verb “have been designed” is correctly written in present perfect tense as the action was done sometime in the past but the effect is felt in the present.
o The simple present tense verb “do”, which stands for “prevent”, correctly presents a general fact in the present context.
• The modifiers are worded and placed correctly.
• This sentence has no errors.

Answer Choice Analysis

Choice A
Correct
• This choice has no errors as already pointed out in the error analysis.
Choice B
Incorrect
• The verb-ed modifier “designed” illogically modifies the preceding noun entity “myrrh trees”. It should modify “natural fences”.
• The present perfect tense verb “have been” incorrectly refers to the simple present tense verb “prevent.” Helping verb “do” should be used to refer to “prevent”.
Choice C
Incorrect
• This choice repeats the present perfect verb tense error of Choice B.
• The list containing two verbs “are designed” and “have” has been connected using comma + and. Whenever a list contains two elements, only and should be used to connect them.
Choice D
Incorrect
• The phrase “naturally built fences” is not the same as “natural fences”. The former means the fences that are built naturally. But the term “natural fences” means they are built of natural material.
• The pronoun “it” does not have any logical antecedent in the sentence. It should be replaced by “they” to correctly refer to the plural noun “fences.”
• Use of the simple present tense “is” is incorrect because it must be followed by the verb “prevented”. But this word is not present in the sentence.
Choice E
Incorrect
• This choice repeats the “naturally built fences” meaning error of Choice D.
• Use of present continuous tense “are being designed” is incorrect because it is not a continuous action. According to the intended meaning of the sentence, the fences have already been designed.
_________________

IMO A;
A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do; correct
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been; last part have been is wrong .
C. natural fences built of myrrh trees are designed for preventing the attacks, and have ; verb ing error
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is ; naturally built is wrong usage
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do; naturally built is wrong usage

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
C. natural fences built of myrrh trees are designed for preventing the attacks, and have
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do

Due to the construction of the sentence, I believe "B" is the answer since these people built the trees by themselves. Another split in the sentence is "to prevent" instead of for preventing as seen in "C" and "D". My final answer is "B"

Posted from my mobile device
_________________

A is the answer.

1. Pay attention to splits: "designed to do smth" vs "designing for doing smth". Of course, "design to do smth" is the correct idiom. Eliminate answers C and D

2. B is wrong because of incorrect parallelism. --> natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been --> extra "they"

3. Another reason why B is wrong is because of wrong usage of ellipsis. Specifically, when you drop a verb, you can only do so if it was present in the exact form before. In answer B "have been" needs to be followed by "preventing". However, we don't have that word before. We only have "to prevent"

4. E is wrong for several reasons. First, incorrect modifier: "naturally built fences". That's not what we want to say and it's definitely what was the original meaning. Second, there's shift in time from "have been" to "are being", which doesn't make sense. Think about it -- if you pick this answer, then you are saying that they are being designed after they have been built. That's nonsense.

IMO A

/*** I believe "the" is missing from all the options or it is not underlined (?)***/

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do - Correct - clear meaning"they (the natural fences) have been designed to prevent" and "they do"
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been - by using "designed to prevent the attacks" as modifier the importance of this part is lost, also what "they have been" doing is unclear
C. natural fences built of myrrh trees are designed for preventing the attacks, and have - to prevent is apt here instead of for preventing, also natural fences "have" what is unclear
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is - to prevent is apt here instead of for preventing, also it is incorrect to point to plural "fences"
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do - "are being designed" means in progress, also they do what is unclear

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do
Seems to be correct.
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
and they have been does not fit correctly. Incorrect
C. natural fences built of myrrh trees are designed for preventing the attacks, and have
and have does not fit correctly. Incorrect
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
and it is does not fit correctly. Incorrect
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do
are being designed is not parallel with have adopted. Incorrect.

Option A seems correct in absence of better option.

IMO A.

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.
Something is adopted and impact is explained. Best usage of tense is present perfect which implies effect of something happened.
Action is needed hene we need simple present verb


A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do Perfectly ok as it describes what natural fence built and they are working as expected
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been :: Needed simple present in the end also trees, designed comma creates a modifier and breaks the sentence
C. natural fences built of myrrh trees are designed for preventing the attacks, and have Wrong tense they are not preventing before they were built
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it isis should eb replaced by plural form
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they doare being designed means work is happening in present and thus they can nto parallely protect also
naturally built fences of myrrh trees are being designed : Something naturally built can not be designed

Answer should be A
_________________

This SC question is test of parallelism and ellipsis.
The later part after AND the verb is to be written after the last word in order to make sense
A. This is our correct answer. This is because the word prevent is our verb and it fits properly after do ( remember ellipsis can't change forms)

B. HAVE been will use Verb +Ing form. Preventing is not used before, so it can't be used
C. for preventing, and have PREVENTED => usage of prevented can't be done because PREVENTED is not present before AND
D. Use of adverb changes meaning from natural fences to naturally built fences. It's actually the natural fences not naturally built fences. Although the error of ellipsis is taken care of here, using is but use of it creates a pronoun mismatch. In place of "it" there should be "they"
E. The use of passive construction is not quite correct. This option also repeats the error of NATURALLY BUILT FENCES vs NATURAL FENCES and thus is INCORRECT.

Correct answer is A.

Regards,
Rishav

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do (prevent the attacks)
this is perfectly parallel and they clearly refer to natural fences (CORRECT)

B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
This incorrectly modify the myrrh trees and convey the meaning that myrrh trees are designed to prevent the attacks
this doesn't make sense so OUT

C. natural fences built of myrrh trees are designed for preventing the attacks, and(subject is required) have
since there is comma before and we require subject after and to make sense so OUT

D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
it is wrong here (it incorrectly refers to fences)----

E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do
how can the naturally built fences be designed.... trying to convey the illogical meaning OUT

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do
Honestly when I dont see any problems in the initial sentence I panick
I dont see any problem here, we have got a good passive voice;
"and they do" says: and they do prevent.

B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
Honestly, I don't see a huge problem with the modifier "designed to prevent the attacks" which in my opinion can modify "natural fences"
The problem for me is "and they have been". "They have been" what? built? Incorrect

C. natural fences built of myrrh trees are designed for preventing the attacks, and have
"and have" still is a problem.
another problem for me is preposition "for" instead of "to"

D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
"and it is" is a problem, I cant find any verb to complete it
naturally is no adverb modifying "built". Incorrect
Still "for" instead of "to"
This choice is truly antihero

E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do
"being" nightmare of a GMAT test taker
"naturally" is incorrectly modifying "built". it has to be adjective and modify "Fence"

Imo
Ans: A

To understand the ellipsis in the sentence, we must first know: what "they do" refers to and emphasizes??
They ---> refers to "fences"
do ---> refers to "prevent" (not design/ not build)
the author wanted to highlight that the fences succeeded to prevent predators

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do (prevent)

B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been (built)
grammatically correct, but this can't be what the author tries to elaborate!!

C. natural fences built of myrrh trees are designed for preventing the attacks, and have
faulty use of preposition "for ,
distorted clause after "and" -->> where is the subject of the clause?? it can't be omitted

D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
faulty use of preposition "for ,
wrong SV agreement with "it". there is no singular subject to refer to!!

E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do
redundant use of "being" , it should be "are designed"

A

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.


Modifier errors
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been

Meaning issues - The fences were designed for a purpose. What's the purpose? To prevent attacks. Thus we need an infinitive to convey intention.
"preventing" requires a helping verb to act as a verb. Right now C is a fragment as it states "subject + participle + are designed for [participle]"
C. natural fences built of myrrh trees are designed for preventing the attacks, and have

Should be "to prevent"; "it" does not agree with plural "fences"
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is

Tense issue - the trees are already designed and built. They aren't currently "being designed" as implied below
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do

A is correct

The the in the underline part MUST be replaced with "their", and this "their" should be kept out of the underlined part (specially for this case).
Also, the underlined part should not include the full-stop (.).
The most important thing for this SC:
It seems that the correct choice is A. If the official answer is A, then it will be considered as faulty construction. Here you go for the reason-->
"have been designed to prevent" has been used as present perfect tense (with passive voice). So. we have to use present continuous tense in the bold part of choice A (considering that choice A is the legit one). As do can't cover are preventing (continuous tense), we have to replace do with are preventing.
Finally, the correct sentence would be as follows:
The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; their natural fences built of myrrh trees have been designed to prevent the attacks, and they are preventing.
^^ This one is the same as:
The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; their (The African Maasai) natural fences built of myrrh trees have been designed to prevent the attacks, and they (natural fences) are preventing.
Hi RonPurewal, MartyTargetTestPrep, jennpt, AjiteshArun, ccooley, DmitryFarber, VeritasKarishma, GMATNinja, egmat, generis
It'll be better for members if you help selecting the correct choice.
Thank you__
_________________

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do. Correct. Correctly presents the S-V agreement between fences and "they" and also using the correct verb tenses, "have been designed" and "they do"
B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been. Incorrect. "they have been" is incorrect verb tense.
C. natural fences built of myrrh trees are designed for preventing the attacks, and have. Incorrect. Wrong verb tense, "are designed"
D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is - Incorrect. S-V disagreement between fences and it towards the end of the sentence
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do. Incorrect. "Being" is almost always wrong on GMAT.

Correct Answer is A.

Original sentence:
The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

Eliminate (D) and (E), as the word "naturally built fences of myrrh trees" is nonsensical. The fences were naturally built and, thus, could not be intentionally designed at the same time.

The sentence in each choice (A), (B), and (C) uses different form of tenses. The sentence "Natural fences have been built .., (have been) designed... and they have been (preventing attacks)" in (B) conveys awfully-confusing timelines. Sentence (C) lacks clarity too. Adding a subject "they" before the verb "have" makes the sentence much clearer.


The best answer is (A). The sentence is grammatically correct and unambiguously conveys the intended timelines and meaning.

Posted from my mobile device

Some months ago when I was reading the last chapter of MGMAT SC guide I came across the following sentence:

Our cars were designed to inspire envy, and they DO. (DO = they DO inspire envy)

Since then I have been waiting for the moment I can apply this knowledge into practice

When we say they DO inspire we can omit inspire and say they DO, but inspire is still meant. Note that the exact verb form missing after the helping verb should be present elsewhere in the sentence. However, the following is wrong:

Our cars were designed to inspire envy, and they WERE. (WERE = they WERE inspire envy)

Saying they WERE inspire is grammatically incorrect. For they WERE to work, the form inspiring would need to be present in the sentence.

Similarly, when we say:

...natural fences have been designed to prevent the attacks, and they DO...

we mean they (fences) DO prevent the attacks. For the above reason have been and have don’t work.

Additionally, we normally say designed for smth or designed to do smth.

Hence A
_________________

though i am somewhat unsure of the question but will try to solve as i would do in actual gmat so go by my strategies

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

A 5 seconds scan
splits
1)placement of myrrh trees
2) have been vs are
3) to prevent vs for preventing

considering its a gmat question for+ ing to show intent is wrong so C and D eliminated
now scan A,B and E


A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do

B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
: ,designed modifier refers to the trees which is absurd

C. natural fences built of myrrh trees are designed for preventing the attacks, and have

D. naturally built fences of myrrh trees have been designed [color=#ff0000]for preventing the attacks, and it is
[/color]
E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do :are being designed so it means process is still in progress and is not the meaning

Grammar: what comes after the semi-colon must be an independent clause (subject+verb) that is in some way related to the previous clause (ie. if you were talking about your cat, then what comes after the semi-colon, must be related to your cat!).

Meaning: a group has adopted a wall to save their livestock from predators, then it gives details about the wall and what it does.

(B) "fences have been built", implies the fences were built in the past, but we intend to say the fences were designed in the past; "trees, designed…" past participle is mod the trees, should refer to the fences, unintended; also, "and they have been" wrong tense and a verb, such as preventing, is missing.
(C) "designed for preventing", they were designed with the intent "to prevent" the attacks, thus we need "to prevent" rather than "for preventing"; also, "and have" what? missing verb.
(D) "designed for preventing", unintended; also, "fences [plural]… trees [plural]" vs. "it [singular]" sva error.
(E) "are being designed…and they do" if the fences are still being designed, how could they have prevented the attacks? tense and unintended.

Answer (A): "the group adopted the wall… fences have been designed to prevent… and they do [prevent the attacks: why? because the group has already adopted them!]"

The African Maasai have adopted the Living Wall project in their bid to save their livestock from attacks by predators; the natural fences built of myrrh trees have been designed to prevent the attacks, and they do.

A. natural fences built of myrrh trees have been designed to prevent the attacks, and they do
No error

B. natural fences have been built of myrrh trees, designed to prevent the attacks, and they have been
use of they have been is incorrect

C. natural fences built of myrrh trees are designed for preventing the attacks, and have
use of only have at the end of sentence is incorrect

D. naturally built fences of myrrh trees have been designed for preventing the attacks, and it is
use of phrase 'naturally built fences' changes the meaning of the original sentence

E. naturally built fences of myrrh trees are being designed to prevent the attacks, and they do
use of phrase 'naturally built fences' changes the meaning of the original sentence

Answer: A