While researching a topic, a student has taken the following notes:Astronomers estimate that the number of comets orbiting the Sun...
GMAT Expression of Ideas : (Expression) Questions
While researching a topic, a student has taken the following notes:
- Astronomers estimate that the number of comets orbiting the Sun is in the billions.
- 81P/Wild is one of many comets whose orbit has changed over time.
- 81P/Wild's orbit once lay between the orbits of Uranus and Jupiter.
- The comet's orbit is now positioned between the orbits of Jupiter and Mars.
The student wants to make and support a generalization about the orbits of comets. Which choice most effectively uses relevant information from the notes to accomplish these goals?
Astronomers estimate that the number of comets orbiting the Sun is in the billions; the comets' orbits may change over time.
Like Uranus, Jupiter, and Mars, billions of comets orbit the Sun.
One example of a comet is 81P/Wild, whose orbit around the Sun once lay between Uranus's and Jupiter's orbits but is now positioned between those of Jupiter and Mars.
A comet's orbit around the Sun may change over time: the orbit of comet 81P/Wild once lay between the orbits of Uranus and Jupiter but is now positioned between those of Jupiter and Mars.
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Astronomers estimate that the number of comets orbiting the Sun is in the billions." |
|
| "81P/Wild is one of many comets whose orbit has changed over time." |
|
| "81P/Wild's orbit once lay between the orbits of Uranus and Jupiter." |
|
| "The comet's orbit is now positioned between the orbits of Jupiter and Mars." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: The notes demonstrate that comet orbits can change over time, using 81P/Wild as a specific example.
Argument Flow: The notes begin by establishing the vast number of comets, then focus on the phenomenon of orbital changes through the specific case of 81P/Wild, showing how its orbit moved from farther out to closer in.
Step 2: Interpret the Question Precisely
What's being asked? We need to find a choice that both makes a generalization about comet orbits AND supports that generalization with evidence from the notes.
What type of answer do we need? A statement that presents a broad claim about comet orbits and backs it up with specific evidence from the research notes.
Any limiting keywords? "most effectively uses relevant information from the notes to accomplish these goals" - specifically to "make and support a generalization about the orbits of comets."
Step 3: Prethink the Answer
- The right answer should make a broad statement/generalization about comet orbits that applies beyond just one comet
- Use the specific evidence about 81P/Wild to support that generalization
- Connect the general principle (orbits change) with the concrete example (81P/Wild's movement)
Astronomers estimate that the number of comets orbiting the Sun is in the billions; the comets' orbits may change over time.
✗ Incorrect
- Makes two separate generalizations but doesn't connect them effectively
- Mentions billions of comets and that orbits "may change" but doesn't use the specific 81P/Wild evidence to support the generalization
Like Uranus, Jupiter, and Mars, billions of comets orbit the Sun.
✗ Incorrect
- Focuses on comparing comets to planets rather than making a generalization about comet orbits
- Doesn't address the key insight about orbital changes over time
One example of a comet is 81P/Wild, whose orbit around the Sun once lay between Uranus's and Jupiter's orbits but is now positioned between those of Jupiter and Mars.
✗ Incorrect
- Presents 81P/Wild as "one example" but doesn't lead with the generalization it's supposed to support
- Works backwards - gives the example first rather than the general principle
A comet's orbit around the Sun may change over time: the orbit of comet 81P/Wild once lay between the orbits of Uranus and Jupiter but is now positioned between those of Jupiter and Mars.
✓ Correct
- Starts with a clear generalization: "A comet's orbit around the Sun may change over time."
- Uses the colon to signal that supporting evidence follows
- Provides the specific 81P/Wild example with both past and present positions as concrete support for the generalization