An agreement question tests whether a verb matches its true subject when extra words come between them. First, sort the verb forms by number: forms used with it or with they. Then ask who or what the verb is about, and set aside the words between commas. One thing takes a singular verb, and more than one takes a plural verb. Nearby nouns don’t decide the match unless they’re part of the subject.
Hints
- Hint 1
Read the second sentence with the words between the commas temporarily left out. What does it call the focus of Chen’s article?
- Hint 2
Replace that subject with it or they, and test the verb forms with that pronoun.
Step-by-step
Find the true subject
Step 1Sort the verb forms
The choices are forms of be, so let’s sort them by number, not tense. Are and were fit they, and have been also fits they. The verb before the focus of Chen’s latest article must match the subject, not a nearby noun.
- Step 2
Remove the extra words
What does the sentence call the focus? Cross out along with the hatchlings’ instinctive sense of direction, the extra words between commas, and This remarkable feat comes right before the blank. An along with phrase doesn’t add another subject the way and would. So the sense of direction doesn’t change the subject’s number. The subject is feat, which names the hatchlings’ trip of more than thirty miles.
- Step 3
Check with a pronoun
Can we shrink This remarkable feat to it or they? A feat is one achievement, so use it to check the verb. The short version is it is the focus, so is gives us the singular form the subject needs. Choice B.