Read both passages and the 12 statements. decide if each statement is supported by
passage a
passage b
both passages
neither passage
a
hanging clear, water-filled bags from doorways is an increasingly popular, and rather unlikely, new method for deflecting annoying—and potentially disease-carrying—flies from building entrances.
some advocates claim that the flies recognize the liquid as the surface of a body of water while others—ludicrously—insist the insect flies away because it is frightened by its own magnified reflection. the most credible explanation, however, concerns the refraction of light.
light rays travel in a straight line. refraction is what happens when something—like a clear object such as a piece of glass or a bag of water—gets in the way. hitting the object changes the ray’s velocity and direction, bending, or refracting, it. refracted rays of light can cause optical illusions, including such things as mirages that even confuse human eyes.
a fly’s head consists primarily of a pair of large complex eyes, each composed of 3,000 to 6,000 simple eyes. this physiology allows the fly to see in multiple directions at once. even though these eyes cannot move or focus on objects like human eyes, they grant the fly a mosaic view of its surroundings, and each simple eye provides one small piece of the puzzle. a housefly bases its sense of direction on the direction sunlight comes from, so when these complex, sensitive eyes experience refracted light, the fly becomes confused and flies away.
although this explanation is persuasive and plausible, research conducted to replicate the results on fly-plagued poultry farms has been inconclusive.
b
while the water-bag method of fly repellent has many supporters, it has at least as many detractors. advocates claim that refracted light in water baffles the flies’ compound eyes. this theory seems quite plausible, but critics classify it as a kind of coincidence masquerading as cause and effect. they say that hanging water bags may seem to work due to the placebo effect. in medicine this is a treatment without therapeutic value, which is administered as if it were a therapy. the "medicine" makes people feel better due to psychological effects rather than due to its curative values. the same effect is likely to occur when people think they are treating a pest problem, and thus notice that the problem seems to diminish.
but what if the placebo even increases the problem? recently, scientists conducted an experiment over the course of thirteen weeks on two egg farms to measure fly activity and encountered just such a situation. they installed commercial, water-based optical fly repellents and concluded that the areas equipped with water bags actually attracted more of these irritating creatures.
since there are reasonable explanations that support the water-bag method and significant evidence that argues against it, it’s up to you whether you keep hanging up water-filled bags around your home or not.
- 1 of 12 -
the passage mentions experiments conducted in an agricultural environment.
passage a
passage b
both passages
neither passage
- 2 of 12 -
the passage makes a convincing case for the effectiveness of the water-bag method.
passage a
passage b
both passages
neither passage
- 3 of 12 -
the passage states that there are more people who do not believe in the water-bag theory than there are supporters of the theory.
passage a
passage b
both passages
neither passage
- 4 of 12 -
the passage suggests that people hang water bags and then notice fewer pests.
passage a
passage b
both passages
neither passage
- 5 of 12 -
the author supports the theory that flies are scared of their own reflection.
passage a
passage b
both passages
neither passage
- 6 of 12 -
the passage mentions the claim that water bags make flies look bigger.
passage a
passage b
both passages
neither passage
- 7 of 12 -
the passage mentions the fact that flies have compound eyes.
passage a
passage b
both passages
neither passage
- 8 of 12 -
the passage states that use of water bags is connected to higher levels of fly activity.
passage a
passage b
both passages
neither passage
- 9 of 12 -
the passage claims that refracted light can affect human optical perceptions.
passage a
passage b
both passages
neither passage
- 10 of 12 -
the passage mentions the claim that refracted light in water confuses flies.
passage a
passage b
both passages
neither passage
- 11 of 12 -
the author of the passage dismisses the water-bag method as ineffective.
passage a
passage b
both passages
neither passage
- 12 of 12 -
the author of the passage cites human beliefs as an explanation.
passage a
passage b
both passages
neither passage
Answer: Neither passage
Explanation: Both passages discuss experiments, but they do not specifically mention them being conducted in an agricultural environment.
- 2 of 12 - The passage makes a convincing case for the effectiveness of the water-bag method.
Answer: Passage A
Explanation: Passage A provides a persuasive explanation for how the water-bag method could be effective in deterring flies, while Passage B presents arguments against the method.
- 3 of 12 - The passage states that there are more people who do not believe in the water-bag theory than there are supporters of the theory.
Answer: Passage B
Explanation: Passage B mentions that the water-bag method has many detractors, implying that there are more people who do not believe in it compared to the number of supporters.
- 4 of 12 - The passage suggests that people hang water bags and then notice fewer pests.
Answer: Neither passage
Explanation: Neither passage explicitly suggests this scenario. Passage A explains the possible reasons for flies being deterred by water bags, while Passage B mentions an experiment that yielded unexpected results.
- 5 of 12 - The author supports the theory that flies are scared of their own reflection.
Answer: Passage A
Explanation: Passage A presents the theory that flies may be frightened by their own magnified reflection as a less credible explanation compared to the refraction of light. This suggests that the author does not fully support the theory of flies being scared of their own reflection.
- 6 of 12 - The passage mentions the claim that water bags make flies look bigger.
Answer: Passage B
Explanation: Passage B mentions the claim that refracted light in water makes flies appear bigger to their compound eyes, suggesting that water bags could deter them.
- 7 of 12 - The passage mentions the fact that flies have compound eyes.
Answer: Both passages
Explanation: Both passages mention the fact that flies have compound eyes, which are composed of multiple simple eyes.
- 8 of 12 - The passage states that the use of water bags is connected to higher levels of fly activity.
Answer: Passage B
Explanation: Passage B mentions an experiment conducted on egg farms which concluded that the areas equipped with water bags actually attracted more flies.
- 9 of 12 - The passage claims that refracted light can affect human optical perceptions.
Answer: Both passages
Explanation: Both passages mention the refraction of light and how it can cause optical illusions and affect human optical perceptions.
- 10 of 12 - The passage mentions the claim that refracted light in water confuses flies.
Answer: Passage A
Explanation: Passage A explains how the refraction of light can confuse flies with their sense of direction, suggesting that it can be used as an explanation for why water bags may deter them.
- 11 of 12 - The author of the passage dismisses the water-bag method as ineffective.
Answer: Neither passage
Explanation: Neither passage dismisses the water-bag method as ineffective. Passage A provides a plausible explanation for how it could work, while Passage B presents arguments against it.
- 12 of 12 - The author of the passage cites human beliefs as an explanation.
Answer: Passage B
Explanation: Passage B mentions the placebo effect and how people's beliefs can influence their perception of the effectiveness of the water-bag method.