Summary
Any female wood duck will lay an egg in the nest of another female wood duck if she sees the other duck leave her nest. Under natural nesting conditions, this behavior is rare because wood duck nests are usually well hidden. However, nesting boxes put up by people undercut the wood duck’s reproductive efforts. Why? Because the nesting boxes become so crowded with eggs that few of them will ever hatch.
Strongly Supported Conclusions
If the nesting boxes put up by people were better hidden, then the boxes would be more successful in aiding the wood duck’s reproductive efforts.
A
Female wood ducks will establish nests in nest boxes only when natural nesting sites are not available.
We don’t know what causes a female wood duck to establish a nest in a nesting box. We only know that female wood ducks will lay eggs in another duck’s nest if she sees that duck leave the nest.
B
Nesting female wood ducks who often see other female wood ducks are the most successful in their breeding efforts.
We don’t know which female wood ducks reproduce most successfully.
C
The nesting boxes for wood ducks have less space for eggs than do natural nesting sites.
We don’t know whether the nesting boxes have less space. We only know that the nesting boxes tend to be overcrowded, but that does not imply that these nesting sights are smaller than natural nesting sites.
D
The nesting boxes would be more effective in helping wood ducks breed if they were less visible to other wood ducks than they currently are.
The argument concludes that the nesting boxes undercut the duck’s reproductive efforts because the boxes become overcrowded. If the cause for overcrowding the nests were reduced, then the effect of undermining reproductive efforts would also be reduced.
E
Nesting boxes are needed to supplement the natural nesting sites of wood ducks because of the destruction of much of the ducks’ habitat.
We don’t know whether the nesting boxes are needed, and we don’t know whether the wood ducks’ habitat is being destroyed.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that marijuana use can cause cancer. This is because the THC in marijuana has been found to inactivate herpesviruses in a study, and inactivated herpesviruses can convert healthy cells to cancer cells.
Notable Assumptions
In order for marijuana to cause cancer, the author must believe that the studies where inactive herpesviruses converted healthy cells to cancer cells must happen under normal biological circumstances in humans. The author must also believe that the cancer-causing effect of THC isn’t offset by some other factor in marijuana. That factor would have to entirely mitigate the conversion of healthy cells to cancer cells by inactive herpesviruses.
A
Several teams of scientists performed the various experiments and all of the teams had similar results.
This reinforces the study that the author cites. We need something to weaken the connection the author makes between marijuana and cancer.
B
The carcinogenic effect of THC could be neutralized by the other ingredients found in marijuana.
While THC alone converts healthy cells to cancer cells, other ingredients in marijuana offset this effect. Thus, marijuana doesn’t cause cancer for the reason the author describes.
C
When THC kills herpesviruses it weakens the immune system, and it might thus diminish the body’s ability to fight other viruses, including viruses linked to cancers.
If anything, this gives another rationale for why marijuana may cause cancer. We’re looking for something that weakens that connection.
D
If chemists modify the structure of THC, THC can be safely incorporated into medications to prevent herpes.
We care about the THC that actually appears in marijuana. We’re not interested in what chemists could potentially do to THC.
E
To lessen the undesirable side effects of chemotherapy, the use of marijuana has been recommended for cancer patients who are free of the herpesvirus.
This is a niche scenario that doesn’t weaken the connection between marijuana and cancer. We’re specifically interested in what THC does to people who do have herpesviruses.
Summarize Argument
The director argues that development costs for the new government-requested vaccine should be subsidized. This is because marketing vaccines is less likely to be profitable than any other pharmaceutical product, since vaccines only need to be administered once and thus sell less than products administered many times.
Notable Assumptions
The director assumes that if the government requests a product, that product should be subsidized to account for the missed profit the company would make from a more marketable product. The director also assumes that relatively lower sales of the vaccine wouldn’t be mitigated by its price or level of sales.
A
Vaccines are administered to many more people than are most other pharmaceutical products.
If the vaccines are administered more widely than most drugs, then the reach of sales would mitigate the fact vaccines are only administered once per patient. This suggests the vaccine will be profitable despite the director’s argument.
B
Many of the diseases that vaccines are designed to prevent can be successfully treated by medicines.
If the vaccine is only one of several pharmaceutical treatment options, it will necessarily be the least lucrative of those. This seems to support the director’s argument.
C
Pharmaceutical companies occasionally market products that are neither medicines nor vaccines.
We’re not interested about some third category of products. The stimulus deals with vaccines and medicines.
D
Pharmaceutical companies other than the Rexx Pharmaceutical Company produce vaccines.
Perhaps those companies should also be subsidized by the government if their vaccines are government-requested. We don’t have enough information here to affect the director’s argument.
E
The cost of administering a vaccine is rarely borne by the pharmaceutical company that manufactures that vaccine.
Even if the cost of administering the vaccine is passed on elsewhere, the manufacturing company still pays the production and marketing costs. These are the costs the director thinks should be subsidized.
Summary
French divers found a cave that is only accessible through an underwater tunnel. The cave was nearly filled with water and contains numerous stalagmites. Stalagmites are stony pillars that are form when drops of water repeatedly fall in the same spot on a cave floor.
Strongly Supported Conclusions
The cave was not always filled with water (because the stalagmites had to form from water dripping on the ground)
A
The Mediterranean Sea was at a higher level in the past than it is now.
This is too strong to support. While it is possible that the water in the Mediterranean Sea was lower in the past, this is too large of an assumption to make. All we know is that there is more water in the cave now.
B
The water level within the cave is higher now than it once was.
This is strongly supported. The cave is now entirely filled with water. Stalagmites only form when drops of water repeatedly land on a single spot. The water must have risen since the stalagmites were formed.
C
The French divers were the first people who knew that the tunnel leading to the cave existed.
There is no evidence for this anywhere in the stimulus. We are not told who discovered the cave first.
D
There was once an entrance to the cave besides the underwater tunnel.
There is no support for this anywhere in the stimulus. Nothing points to there being another entrance.
E
Seawater in the Mediterranean has a lower mineral content now than it had when the stalagmites were being formed.
This is far too strong of a statement to support. The mineral content of the water does not play any major role in these statements. You need to make a lot of assumptions to make this work