Question 221·Medium·Form, Structure, and Sense
In a recent survey, a panel of leading climate scientists ______ that the frequency of extreme weather events has increased significantly over the past decade.
Which choice completes the text so that it conforms to the conventions of Standard English?
For subject-verb agreement questions, first strip away extra phrases (especially prepositional phrases like "of leading climate scientists") to isolate the true subject. Decide whether that subject is singular or plural, then quickly eliminate any verb forms that do not match that number or that are not in a simple, appropriate tense for the context. When collective nouns such as "panel," "team," or "committee" are acting as one unit, treat them as singular and pair them with singular verbs ("panel asserts," "team wins").
Hints
Locate the true subject
Ignore the prepositional phrase "of leading climate scientists." What is the one main noun that the verb must agree with?
Singular or plural?
Think about whether that main noun refers to one group or many individuals acting separately. Should the verb be singular or plural?
Check each verb form
Which choice is a simple present-tense verb that correctly matches a singular third-person subject like "the panel" and can serve as the main verb of the sentence?
Watch out for helping verbs and -ing forms
Any answer that uses a helping verb like "have" or an -ing form like "asserting" must fit grammatically in the sentence as written. Ask if the structure still works when you plug it in.
Step-by-step Explanation
Identify the sentence’s subject
Look at the main noun that the verb must agree with: "a panel of leading climate scientists." The core subject here is panel, not scientists.
The phrase "of leading climate scientists" is a prepositional phrase describing the panel. It does not change the subject from singular to plural.
Decide if the subject is singular or plural
The word panel is a collective noun referring to a single group. In Standard English, collective nouns like "panel," "team," or "committee" are usually treated as singular when they act as one unit.
So, the subject panel needs a singular verb form.
Eliminate verbs that do not match a singular subject
Now check each option for subject-verb agreement and form:
- "assert" is the base form used with plural subjects (they assert) or with "I" and "you" (I assert, you assert), not with a singular third-person noun like "panel."
- "asserting" is an -ing form (present participle/gerund) and cannot stand alone as the main verb in this sentence.
- "have asserted" uses "have," which is the plural auxiliary; a singular subject would require "has asserted."
Only one remaining option is a singular present-tense verb that can correctly follow "a panel" and serve as the main verb in this sentence. That option is the correct answer.