Question 242·Medium·Form, Structure, and Sense
A series of unexpected delays, including a shortage of critical components, _____ the launch date of the satellite.
Which choice completes the text so that it conforms to the conventions of Standard English?
For verb-agreement questions, first strip away prepositional phrases (like "of unexpected delays") and clauses or phrases set off by commas to reveal the core subject and verb. Decide whether the subject is singular or plural, then match that with the correct verb form. Next, use context clues (time words, whether the action is completed or ongoing, and whether it’s a one-time event or a general truth) to choose the appropriate tense and aspect. Eliminate any choices that either disagree in number with the subject or give a time meaning that doesn’t fit the sentence.
Hints
Find the true subject
Cover up the phrase between the commas (", including a shortage of critical components,") and the phrase "of unexpected delays." What is the main noun left doing the action?
Check singular vs. plural
Ask yourself: Is that main noun referring to one thing or more than one thing? The verb must match that number.
Think about the time of the action
Do the delays sound like a finished set of events that have already affected the launch date, or like a general truth that happens regularly? Choose the verb form that best fits that time meaning.
Step-by-step Explanation
Identify the sentence’s subject
Ignore the phrases between commas and the prepositional phrase starting with "of." The core sentence is:
- "A series __ the launch date of the satellite."
So the subject is "A series", not "delays."
Decide if the subject is singular or plural
The word "series" is singular here, because it is preceded by "A" ("A series"). The phrase "of unexpected delays" just describes what kind of series it is.
A singular subject needs a singular verb form.
Choose the appropriate tense for the meaning
The sentence talks about delays that have already happened and have affected the launch date. This is an action in the past with a result that matters now (the launch date is now later than originally planned).
That meaning is usually expressed with the present perfect tense ("has/have" + past participle).
Match number and tense to pick the answer
We need a verb that is:
- Singular (to match "A series")
- In the present perfect tense (to show past delays affecting the current launch date)
Among the options, only "has postponed" is singular and in the present perfect tense, so the correct answer is B) has postponed.