A list punctuation question with descriptions after the items tests where one item ends and another begins. Read the whole sentence and group each item with its description, then ask where the blank falls. Check what each mark separates: commas separate simple items, and semicolons separate items with commas inside them. A period needs complete sentences on both sides; a colon introduces a list or explanation after a complete sentence. Wrong choices often break a list into pieces that can't stand alone.
Hints
- Hint 1
Start with the things engineers evaluate. Which words name each thing, and which words describe it?
- Hint 2
Compare the marks inside an item with the mark between items. Where does each item end, and where does its description end?
Step-by-step
Follow the list's separators
Step 1Group each item with its description
The words engineers evaluate the expected radiation intensity start a list of things engineers check, so we're choosing punctuation within that list. What belongs to each item? The text links radiation intensity to orbit and circuitry's tolerance to materials. It then links availability of shielding to weight constraints. Each item includes the thing engineers evaluate and its description.
- Step 2
Read the existing separator
What mark already separates whole items? In which varies by orbit; the circuitry's tolerance, a semicolon separates the radiation item from the circuitry item. The commas before which stay inside the items, attaching each description to what it describes. Items that contain commas need semicolons between them, so the reader can tell where a description ends and the next thing engineers evaluate begins.
- Step 3
Test a new sentence or explanation
The shielding item still belongs to the list after engineers evaluate. Can the version with a period or the version with a colon keep it in the list? With the period, is limited belongs to which is limited by weight constraints, so the availability of shielding has no main verb and can't stand alone. A colon introduces a list or explanation; it can't separate shielding from the other equal items engineers evaluate.
- Step 4
Complete the list
At the blank, the item about circuitry's tolerance ends, and the shielding item begins. A comma would blur that boundary with the commas inside the items. A semicolon matches the list's existing separator, and and introduces the final item. Choice C.