After an oil spill, rehabilitation centers were set up to save sea otters by removing oil from them. The effort was not worthwhile, however, since 357 affected live otters and 900 that had died were counted, but only 222 affected otters, or 18 percent of those counted, were successfully rehabilitated and survived. Further, the percentage of all those affected that were successfully rehabilitated was much lower still, because only a fifth of the otters that died immediately were ever found.
Summarize Argument
The author concludes that the effort to save sea otters by removing oil from them wasn’t worthwhile. He supports this by saying that only 18% of counted otters were successfully rehabilitated and that this percentage is actually even lower because only a fifth of the otters that died immediately were ever found.
Notable Assumptions
The author assumes that a low success rate means that the rehabilitation effort wasn’t worthwhile, ignoring the possibility that a small number of rehabilitated otters might have significant positive ecological value or long-term benefits.
He also assumes that the reported number of otters is accurate, without addressing the possibility that the dead otters that were never found can’t be accurately counted. (?)
Note: We’re looking for the answer choice that “calls into question evidence offered in support of the conclusion.”
A
Do sea otters of species other than those represented among the otters counted exist in areas that were not affected by the oil spill?
The author’s argument only addresses rehabilitation efforts among the otter population that was affected by the oil spill. Surely other otter species exist in other places, but their existence doesn’t call into question the evidence offered in support of the author’s conclusion.
B
How is it possible to estimate, of the sea otters that died, how many were not found?
This calls into question the author’s evidence. He claims that the percentage of successfully rehabilitated otters is much lower than 18% because only a fifth of the dead otters were ever found. But how can he know that this number is accurate if the otters were never found?
C
Did the process of capturing sea otters unavoidably involve trapping and releasing some otters that were not affected by the spill?
Like (A), the author’s argument is only concerned with those otters that were affected by the spill. The effects of the rehabilitation process on other otters doesn’t call into question his evidence, which only addresses affected otters.
D
Were other species of wildlife besides sea otters negatively affected by the oil spill?
The author’s evidence only addresses sea otters that were affected by the oil spill. Whether other species of wildlife were also affected is irrelevant, since the rehabilitation efforts in question only involved sea otters.
E
What was the eventual cost, per otter rehabilitated, of the rehabilitation operation?
The author doesn’t mention cost as a factor in his assessment of whether the rehabilitation effort was worthwhile. (E) thus doesn’t call into question the author’s evidence, which only addresses the percentage of otters that were rehabilitated.
A
Adobe is a suitable substitute for other building materials where the heat-conduction properties of the structure are especially important.
B
In the desert, adobe buildings remain cool during the heat of the day but retain the warmth of the sun during the cool evenings.
C
Because adobe conducts heat very slowly, adobe houses maintain a pleasant, constant temperature.
D
Ideally, a material used for building houses in desert environments should enable those houses to maintain a pleasant, constant temperature.
E
Adobe is an especially suitable material to use for building houses in desert environments.
A
The first study was carried out at the time of year when plants of the species are at their most populous.
B
The first study, but not the second study, also collected information about patterned stems in other plant species.
C
The second study included approximately 15 percent more individual plants than the first study did.
D
The first study used a broader definition of “patterned.”
E
The focus of the second study was patterned stems, while the first study collected information about patterned stems only as a secondary goal.