Answer: He argued that observation and experimentation are the most important tools for understanding the natural world. ... It caused people to take a new, logical approach to scientific discovery based on experimentation and observation.
The message is understood but the sentence is not well written. You should write "Logos, that is the appeal of logic, consists of persuation backed up with actual observation, data, and facts". While the word Logos can be paraphrased as 'the appeal of logic', it is necessary to clarify the function of Logos in a text. With that purpose in mind, it is neccesary to separate the ideas of persuation from the paraphrase.
Answer:
<span>B. Singular subjects need singular verbs while plural subjects need plural verbs.
The agreement consists in that the number of the verb and the number of the subject need to be the same: if the subject is singular the verb has to be singular, and if the subjetc is plural the verb has to be plural.
Verb-subject disagreement is a grammatical error.
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