The golden toad of Costa Rica.. (NEW INFerence question)

[roy.ananda]

Additionally, the next question about the passage contradicts the answer choice for this question. The next question is:

The passage implies that

(a) the Monteverde area may be home to toad or frog species that have not yet been noted by researchers

(b) the Monteverde Cloud Forest Preserve was not large enough to protect the golden toad

(c) only Costa Rican amphibians living near Monteverde have disappeared since the 1980s

(d) if amphibians did not have permeable skin, then they could not act as biological harbingers

(e) more than one third of the world’s amphibian species have become extinct

Here,the OA is A),explaining that The last sentence of the first paragraph says that a certain proportion of the species of frogs and toads known to once inhabit an area near Monteverde have disappeared. The language known to indicates that the author is hedging: a total of fifty species are known to live there, but others might exist that have not yet been found or formally catalogued.

Dear instructors,would you explain how to conclude that the author is hedging based on his language in this context?Also,if you can provide more explanations like this one,it will be appreciated.

Thanks in advance,
Anand

[RonPurewal]

think about the difference between "This city is home to 12,302 individuals who have AIDS" and "This city is home to 12,302 individuals known to have AIDS".

the first of these implies a complete count.

the only reason anyone would ever write the second version is to indicate that there may be others who have the disease unknowingly.

[RonPurewal]

more importantly-- if you're going to try to reject an answer choice, you'd better be able to defend a different choice!

if you don't like that choice, which choice do you think should be the correct answer?

[roy.ananda]

more importantly-- if you're going to try to reject an answer choice, you'd better be able to defend a different choice!

if you don't like that choice, which choice do you think should be the correct answer?

I was doubtful here.I have chosen option E but again the language 'more than one third of the world’s amphibian species have become extinct' seems extreme.The passage contains info that between one third and one half of the world’s amphibian species—including frogs, toads, and salamanders—have declined or disappeared.Can we compare decline or disappearance in this context with extinction?

[RonPurewal]

if the population of a species has "disappeared", then that species is extinct.

if the population has "declined", then it is not (yet) extinct.

[zhengs482]

my question is about answer choice d——
“if amphibians did not have permeable skin, then they could not act as biological harbingers；”
i thought this sentence means " if amphibians did not have permeable skin, then they might not act as biological harbingers.", so i choose d.
because d just points out that the unique skin is one of the reasons that cause amphibians act as biological harbingers.
does "could" in this sentence means "definitely could not"?

[Sage Pearce-Higgins]

A tricky point about English! 'Could' and 'might' have similar meanings in some contexts, such as 'It could rain' or 'It might rain'. However, 'could not' and 'might not' are totally different. Take a couple of examples:
He could not walk to school. (Definitely not happening; perhaps he has an injury, or is just very busy.)
He might not walk to school. (It's uncertain, but possible.)

[zhengs482]

A tricky point about English! 'Could' and 'might' have similar meanings in some contexts, such as 'It could rain' or 'It might rain'. However, 'could not' and 'might not' are totally different. Take a couple of examples:
He could not walk to school. (Definitely not happening; perhaps he has an injury, or is just very busy.)
He might not walk to school. (It's uncertain, but possible.)

thanks a lot!

[Sage Pearce-Higgins]

You're welcome.

[ElijahS782]

I have a similar questions about the answer for the question "The passage implies that...".

I eliminated all but A and D and guessed. I thought I saw flaws in both during the practice exam. I found A ambiguous because I thought 'known' could imply writer didn't know the number of species or that the writer didn't know the area in which they lived. For example, "Rattlesnakes are known to live in Texas." This statement implies that they might live elsewhere. Answer D I didn't like either because, just like the answer key says, it's a bit too far of a stretch in logic. The answer is A.

My question is about the use of 'known' in this context. Is there an unspoken constraint pertaining to the word use, or is there something else in the sentence that would eliminate the ambiguity in which word 'known' casts uncertainty on, or could it apply to either? Or both?

My current train of thought is that it could apply to either based on sentence structure, therefore it casts uncertainty on both, which would still leave A as the answer. It would also mean that the made up answer statement "....these frog and toad species may live outside of the area near Monteverde" would be a correct answer.

Thanks in advance for the assist.

[Sage Pearce-Higgins]

Please state the whole problem when asking a question about an RC problem (even if it's been stated earlier in the thread).

As for your discussion of 'known', I assume that you're referring to this sentence from the passage: 'Since that time, another twenty of the fifty species of frogs and toads known to once inhabit a 30 square kilometer area near Monteverde have disappeared.'

It's good to focus in on a word or phrase to think what is it really saying. Your example - "Rattlesnakes are known to live in Texas." - is a good one as it highlights what we might not know, i.e. the other places that rattlesnakes live. In the passage, stating that fifty species of frogs and toads are known to inhabit this area implies that there may be more species, yet undiscovered.

As for who's doing the 'knowing' in this context, I think that it's a reasonable assumption with our use of language that 'is / are known' suggests a general level of knowledge by, say, the scientific community. It would sound odd to use the construction 'is known' for personal knowledge, e.g. 'It is known that my flatmate will go out this evening.'

Finally, note how, in inference questions, we can be suspicious of strong claims. If you're left with a guess between a vague, dull sounding answer such as answer A, and a bold claim such as answer D, pick A.

[AravindV829]

"The passage implies that
A) the Monteverde area may be home to toad or frog species that have not yet been noted by researchers
B) the Monteverde Cloud Forest Preserve was not large enough to protect the golden toad
C) only Costa Rican amphibians living near Monteverde have disappeared since the 1980s
D) if amphibians did not have permeable skin, then they could not act as biological harbingers
E) more than one third of the world’s amphibian species have become extinct
"

It feels like a bit of a stretch to call A correct.
The passage says:

"Since that time, another twenty of the fifty species of frogs and toads known to once inhabit a 30 square kilometer area near Monteverde have disappeared".

It doesn't say that it was actually in the Monteverde area.
Given that Monteverde is a reserve, is it not more reasonable to assume that Frogs in Monteverde have been studied more than frogs in areas NEAR Monteverde, than otherwise?

To me it feels like the assumptions in A & E are similar in that they don't stretch too much.

[Sage Pearce-Higgins]

To be clear, we're not dealing with an assumption question here. This is an inference problem. By inference, we mean 'something that must be true based on the information in the passage'. Check out the strategy guide Evidence chapter for more on this.

Here, it's reasonable to interpret "a 30 square kilometer area near Monteverde" as the same as "the Monteverde area". The text tells us about some 'known' species in the area, and it's safe to deduce that there might be some unknown species in that area.

Note that, for inference problems, a good guessing strategy is to be suspicious of strong wording in answer choices. After all, it's easier to find evidence to support a statement such as 'some people may like peanut butter' than it is to support 'all people definitely like peanut butter'.