This sentence does not contain a comma where one is necessary. The phrase "While looking through the company's books" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. The correct answer choice is, "the company's books, the accountant found many errors."

This sentence does not contain a comma where one is necessary. The words "small" and "fast" are coordinate adjectives: adjectives that modify the same noun separately, but are not separated with a conjunction. Coordinate adjectives need to be separated with a comma. The correct answer choice is, "The small, fast car was representative of many innovations."

This sentence misuses a comma. This sentence combines two independent clauses without the use of a conjunction. The necessary punctuation for this spot is a semicolon, which should appear after the word "town." No additional punctuation is needed. The correct choice is, "one of the largest in the town; he had been collecting these items for many years."

This sentence does not contain a comma where one is needed. The phrase "after running" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. The correct choice is: "After running, he decided to eat a snack and watch."

This sentence contains a comma where one is not necessary. Commas are usually used to separate two different clauses, but the phrase "that he wanted to open up an animal sanctuary" is a part of the same clause as the previous phrase: "He loved animals so much." The comma should be omitted. The correct choice is: "He loved animals so much that he wanted to open up an animal sanctuary."

In this sentence, a comma incorrectly separates the subject from modified verb of the sentence. "Jeremy" is not an introductory word or phrase, it is a proper noun acting as the subject of this sentence. This is a simple sentence that requires no punctuation.

This sentence does not contain a comma where one is necessary. The phrase "Though many people loved the brand" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. The correct choice is, "the brand, Abigail felt the product was overrated."

This sentence contains an error in the usage of the comma. Commas should only appear before a coordinating conjunction like "and" when the conjunction joins two independent clauses. The phrase "took much pride in the pieces that adorned her walls" is not an independent clause, however. If the phrase had the word "she" before the word "took," then the comma would be appropriate. The correct choice is, "a collector of fine arts and took much pride in the peices."

This sentence misuses a comma. Commas can only be used to combine independent clauses when a conjunction is present. This is not the case. When a conjunction is not present, the most appropriate punctuation in this case is a semicolon. Note that a colon would not be appropriate since the second clause, while related, does not actually explain anything about the act of collecting the stamps. The correct choice is "had been collecting stamps for years; her collection is now filled."

This sentence misuses a comma. Commas are generally used to separate clauses, but a prepositional phrase (here: "in hope of finding a rare book") does not start a new clause. Commas generally do not appear before prepositions. The correct chocie is "the library in hope of finding a rare book." The other choices contain dangling prepositions or the same error in using the comma (among others).