Safety expert: Tuna is often treated with carbon monoxide so that it will not turn brown as it ages. Treating tuna with carbon monoxide does not make it harmful in any way. Nonetheless, there is a danger that such treatment will result in more people getting sick from eating tuna.
"Surprising" Phenomenon
Why might treating tuna with carbon monoxide cause more people to get sick from eating tuna when the carbon monoxide treatments don’t make the fish harmful in any way?
Objective
The right answer will introduce some reason why treating tuna with carbon monoxide might cause more people to get sick from eating tuna. That reason cannot be a direct health risk of the carbon monoxide treatment, because the stimulus tells us that the treatment doesn’t make the tuna harmful. Instead, the answer must describe some causal impact that the treatments have on the way tuna is consumed.
A
Workers in fish processing plants can be sickened by exposure to carbon monoxide if the appropriate safety procedures are not followed at those plants.
The stimulus says that the carbon monoxide treatments might cause more sickness specifically from eating tuna. If we were looking for a reason why the carbon monoxide treatments might cause more people to get sick in general, this would be perfect.
B
Over the last several years, tuna consumption has increased in most parts of the world.
This has nothing to do with the carbon monoxide treatments, so it doesn’t help resolve the discrepancy.
C
Tuna that is treated with carbon monoxide provides no visible indication when it has spoiled to the point that it can cause food poisoning.
This explains why treating tuna with carbon monoxide might cause more people to get sick from eating tuna: if people can’t see that the tuna has gone bad, they might eat spoiled tuna (ew) and get sick! With untreated tuna, people are more likely to see when the fish goes bad.
D
Treating tuna with carbon monoxide is the only way to keep it from turning brown as it ages.
This doesn’t provide any information about how the carbon monoxide treatments might lead to more people getting sick from eating tuna, so it doesn’t help resolve the discrepancy.
E
Most consumers strongly prefer tuna that is not brown because they believe that brown tuna is not fresh.
This might explain why companies would want to treat their tuna with carbon monoxide, but it doesn’t provide any information about why the treatments might lead to more people getting sick from eating tuna.
A
No other GRBs with unusual properties have been sighted.
B
The classification of GRBs can sometimes be made on the basis of duration alone.
C
Properties other than duration are more important than duration in the proper classification of the unusual GRB.
D
GRBs cannot be classified according to the different types of cosmic events that create them.
E
Descriptive labels are easily replaced with nondescriptive labels such as “type I” and “type II.”
Dentist: I recommend brushing one’s teeth after every meal to remove sugars that facilitate the growth of certain bacteria; these bacteria produce acid that dissolves minerals in tooth enamel, resulting in cavities. And when brushing is not practical, I recommend chewing gum—even gum that contains sugar—to prevent the formation of cavities.
"Surprising" Phenomenon
Why would chewing sugary gum after a meal help to prevent cavities when sugar is known to lead to the formation of cavities?
Objective
The right answer will be a hypothesis that explains why chewing gum after a meal helps to prevent the formation of cavities. That explanation must offer some dental hygiene benefit of chewing gum that has the potential to outweigh any damage that could be caused by the sugar in some gums.
A
A piece of chewing gum that contains sugar contains far less sugar than does the average meal.
We would expect this to be true—think of how small a piece of gum is! This answer doesn’t explain why chewing gum helps to prevent cavities, though, so it doesn’t reconcile the paradox in the stimulus.
B
Tooth decay can be stopped and reversed if it is caught before a cavity develops.
While this might be relieving to hear on a personal level, it doesn’t help to reconcile the paradox at hand. We need information about how chewing gum after meals helps to prevent cavities, and this answer choice doesn’t give us that.
C
Chewing gum stimulates the production of saliva, which reduces acidity in the mouth and helps remineralize tooth enamel.
This is helpful! Sugar leads to cavities because it causes enamel to dissolve, but chewing gum protects enamel. It makes sense, then, that chewing gum after meals helps to prevent cavities even if the gum contains some sugar.
D
Sugars can be on teeth for as long as 24 hours before the teeth-damaging bacteria whose growth they facilitate begin to proliferate.
This answer choice has nothing to do with the cavity-prevention benefits of chewing gum after meals, which is what we need the answer to explain!
E
Chewing gum exercises and relaxes the jaw muscles and so contributes to the overall health of the oral tract.
This answer doesn’t help because it has nothing to do with the impact that chewing gum has on cavity formation. The “overall health of the oral tract” could refer to factors other than cavities.
A
The unearthed land mammal is only one of several ancient land mammals that were indigenous to New Zealand.
B
The recently discovered land mammal became extinct long before the native bird population was established.
C
The site at which the primitive land mammal was unearthed also contains the fossils of primitive reptile and insect species.
D
Countries with rich and varied native land mammal populations do not have rich and varied native bird populations.
E
Some other island countries that are believed to have no native land mammals in fact had indigenous land mammals at one time.