To determine whether a satellite can survive a solar storm, engineers evaluate the expected radiation intensity, which varies by orbit; the circuitry's tolerance, which depends on its _____ of shielding, which is limited by weight constraints.
Which choice completes the text so that it conforms to the conventions of Standard English?
When a sentence contains a series whose individual items already include commas, first identify the full extent of each item. Use semicolons consistently between those complex items, including before the coordinating conjunction that introduces the final item.
Hints
Find the objects of the verb
Identify everything that the engineers “evaluate.” How many parallel items follow that verb?
Notice the internal punctuation
Each listed item contains a modifying clause beginning with “which.” Consider how the commas inside those items affect the punctuation needed between them.
Compare parallel boundaries
Notice how the first item is separated from the second. Decide whether the boundary before the parallel third item should work in the same way.
Step-by-step Explanation
Identify the series
The verb “evaluate” introduces three objects:
- “the expected radiation intensity, which varies by orbit”
- “the circuitry's tolerance, which depends on its materials”
- “the availability of shielding, which is limited by weight constraints”
Distinguish the two levels of punctuation
Each listed item contains an internal comma that introduces a modifying clause beginning with “which.” The sentence therefore uses stronger punctuation to mark the boundaries between the three full items.
Use the existing boundary as evidence
A semicolon already separates the first item from the second. Because the second and third items are at the same level in the series, the boundary before the third item should use the same punctuation.
Complete the series
The completed sentence reads: “To determine whether a satellite can survive a solar storm, engineers evaluate the expected radiation intensity, which varies by orbit; the circuitry's tolerance, which depends on its materials; and the availability of shielding, which is limited by weight constraints.”