Final answer:
The sentence correctly using an apostrophe in a contraction is: "The tornado's approach sent everyone running for cover." It correctly shows possession for the word tornado. It is important to differentiate between contractions and possessive pronouns, which do not use an apostrophe.
Step-by-step explanation:
The sentence that shows the correct use of an apostrophe in a contraction is, "The tornado's approach sent everyone running for cover." In this sentence, the apostrophe signifies possession, indicating that the approach belongs to the tornado. Contractions combine two words into one and use an apostrophe to signal the omission of letters. It is important to not confuse contractions with possessive pronouns, which do not require apostrophes, as well as to be aware of the correct placement of apostrophes in plural nouns and verbs.
Common mistakes include misusing its/it's and their/they're/there. Remember, its is a possessive pronoun and does not require an apostrophe, whereas it's is a contraction for "it is" or "it has". Similarly, their is a possessive pronoun, there indicates a place, and they're is a contraction for "they are."