Ikrimah

 A paragraph is a series of sentences that are organized and coherent, and are all related to a single topic. Almost every piece of writing you do that is longer than a few sentences should be organized into paragraphs.

 grammar is a system of rules that allow us to structure sentences. It includes several aspects of the English language, like: Parts of speech (verbs, adjectives, nouns, adverbs, prepositions, conjunctions, modifiers, etc.)

 science is a systematic effort using scientific methods in the development and structuring of knowledge as proven by explanations and predictions that have been tested as human understanding of the universe and its world. These aspects must be limited to produce definite formulations