A
Massive doses of aspirin and vitamins enhance athletic performance.
B
Addictive drugs are just as unnatural as nonaddictive drugs like aspirin and vitamins.
C
Unnecessary deaths and injuries occur in other walks of life besides modern sports.
D
There would be more unnecessary deaths and injuries if it were not for running shoes, boxing gloves, and bodybuilding machines.
E
Taking massive doses of aspirin or vitamins can be physically harmful.
A
A larger number of 18-year-old high school graduates were recruited for the republic’s armed services in 1986 than in 1980.
B
Many of the high-technology systems used by the republic’s armed services can be operated only by individuals who have completed a high school education.
C
Between 1980 and 1986 the percentage of high school graduates among 18-year-olds recruited in the republic rose sharply.
D
Personnel of the republic’s armed services are strongly encouraged to finish their high school education.
E
The proportion of recruits who had completed at least two years of college education was greater in 1986 than in 1980.
Science journalist: Brown dwarfs are celestial objects with more mass than planets but less mass than stars. They are identified by their mass and whether or not lithium is present in their atmospheres. Stars at least as massive as the Sun have lithium remaining in their atmospheres because the mixing of elements in their internal nuclear furnaces is incomplete. Stars with less mass than the Sun have no lithium because the element has been fully mixed into their nuclear furnaces and consumed. A brown dwarf does not have a fully functional nuclear furnace and so its lithium cannot be consumed.
Summary
Brown dwarfs are more massive than planets but less massive than stars. They are identified by their mass and whether or not lithium is present in their atmospheres. A brown dwarf’s lithium cannot be consumed because they do not have a functional nuclear furnace.
Strongly Supported Conclusions
If a celestial object does not have lithium in its atmosphere, then it is not a brown dwarf.
A
Any celestial object without lithium in its atmosphere is a star with less mass than the Sun.
This answer is unsupported. We don’t know from the stimulus that any celestial object without lithium must be a star. We only know from the stimulus that some stars do have lithium in their atmospheres.
B
Any celestial object with lithium in its atmosphere has a nuclear furnace that has incompletely mixed the object’s elements.
This answer is unsupported. We know that this is true of stars at least as massive as the sun, but saying this is true of any celestial object is too strong.
C
No celestial object that has no lithium in its atmosphere is a brown dwarf.
This answer is strongly supported. We know that brown dwarf’s must have lithium in their atmospheres because it cannot be consumed by a nuclear furnace.
D
No celestial object with lithium in its atmosphere has less mass than the Sun.
This answer is unsupported. This is the reverse relationship from the stimulus. The stimulus tells us that if a star is at least as massive as the sun, then there is lithium in that star’s atmosphere.
E
No celestial object less massive than a brown dwarf has lithium in its atmosphere.
This answer is unsupported. We don’t know anything about celestial objects with less mass than brown dwarfs from the stimulus. The stimulus is limited to brown dwarfs and celestial objects with greater mass.