Although exposure to asbestos is the primary

[tim]

in general, this can often be a very helpful strategy for CR problems..

[lindaliu9273]

Can someone help clarify the reason why (B) is wrong?

(B) says --> Modified vaccine prevents SV40 contamination. Doesn't this strengthens the fact that the vaccine contained SV40 at first place, which is researcher's hypothesis?

that is not the hypothesis here; in fact, that is a known fact. the argument states explicitly that "in 1960 some polio vaccine was contaminated with the virus"; there can be no debate about this fact.

the hypothesis in this argument is that this sv40 -- the sv40 that got into the polio vaccine in 1960 -- is the same sv40 that was found in the cancers later on.
since we are only concerned with whether the 1960 polio vaccine spread the virus, later changes in the procedure for manufacturing the vaccine are irrelevant.

Hi Ron,

But does B rule out the possibility that "vaccine later than 1960 contain the virus and cause mesotheliomas "? Is it a kind of support?

Thank you.

[RonPurewal]

1/
According to the passage, mesotheliomas are "slow-developing". Since choice B talks about what is now possible"”"”implying recent changes"”"”it's irrelevant to anything in the required timeframe.

2/
Notwithstanding point 1, if this sort of contamination were a regular occurrence, or at least something that could be expected to occur regularly (like, say, an earthquake or flood), then there'd be more of a point here.
This particular situation, though"”"”the contamination of a vaccine with a virus from another species"”"”is best read as an utterly freakish one-time event.

[RichaChampion]

Need a little help on eliminating (C), please.

Thanks.

(c) doesn't help; it merely confirms what we already know.
specifically:
it tells us that "recently discovered samples of the vaccine dating from 1960 still show traces of the virus."
in other words, choice (c) tells us only that the virus was/is present in some 1960-era vaccines.

the problem is that we already know this: the passage tells us, after all, that "in 1960 some polio vaccine was contaminated with the virus".

(c) adds absolutely nothing new beyond this already-established fact.

Ron Sir,

Based on your above discussion we can conclude that strengthen and weaken questions requires some additional information in answer choices.

[RonPurewal]

well, yeah -- of course you need new information to strengthen or weaken an argument!

this isn't something you need to memorize -- this is just normal common sense. if you have an argument, and you need to make it STRONGER or BETTER, then ... well, you can't just say the same stuff you've already said!

[RichaChampion]

well, yeah -- of course you need new information to strengthen or weaken an argument!

this isn't something you need to memorize -- this is just normal common sense. if you have an argument, and you need to make it STRONGER or BETTER, then ... well, you can't just say the same stuff you've already said!

Oh Yes that make sense. This is not to be memorized, but a common sense. My point was their are answer choices that just paraphrase or rephrase the argument they can be discarded straightaway.

[tim]

Exactly!

[RonPurewal]

correct.