Which one of the sentences is a subject verb agreement and why 2a Peer editing academic papers require critical-thinking skills diplomacy?

The sentence "Peer editing academic papers require critical-thinking skills and diplomacy" is incorrect in terms of subject-verb agreement.

Here's why:

* Subject: The subject of the sentence is "peer editing academic papers". This is a plural noun phrase, indicating multiple papers being edited by peers.

* Verb: The verb "require" is in the singular form.

To correct the sentence for subject-verb agreement, the verb should be plural:

Correct sentence: Peer editing academic papers require critical-thinking skills and diplomacy.