A sentence completion question with verbs and commas in the choices tests whether the sentence’s main parts fit together. Sort the choices by whether they add a main verb, then read to the period to find the subject’s verb. Cross out extra information between them to check what remains. Without a joining word, a subject can’t take a second main verb; a detail in the middle needs matching marks on both sides.
Hints
- Hint 1
Read from the blank to the period. Find the main verb, checking whether the commas interrupt words that belong together.
- Hint 2
Try reading the sentence without the phrase about the Brooklyn Bridge. Does what remains have a subject and main verb, and how does the phrase fit with the words on either side?
Step-by-step
Count verbs and match commas
Step 1Find the subject and sort the added verbs
The opening Civil engineer Emily Warren Roebling’s on-site tells us whose directives we’re reading about. Is the subject Roebling or her directives? The directives are the subject, because her name shows who they belong to. The versions with were and had been add main-verb forms, so let’s find out whether the directives already have a main verb.
- Step 2
Read across the time detail
Read past the blank to were, for decades, omitted from formal accounts of the project. What words say what happened to the directives? The main verb is were omitted, which says the directives were left out of the accounts. The commas around for decades show extra information, so those words interrupt the verb without replacing it.
- Step 3
Test the bridge detail
What does vital to the completion of the Brooklyn Bridge add? It describes the directives as needed to finish the bridge, so it isn’t another main verb. Cross out that description and the time detail, and the remaining sentence says Roebling’s directives were omitted from the accounts. The bridge detail is extra information, and its closing comma sits right before the main verb.
- Step 4
Add the opening comma
The versions directives were, directives, were, and directives had been each add a second main verb without a joining word. The comma closing vital to the completion of the Brooklyn Bridge needs a matching comma at the start of that detail. We need the opening comma without another verb, which directives, gives us. Choice C.