Which of the following sentences is punctuated correctly?

The Krebs cycle, part of cellular respiration, happens in the mitochondria. Fermentation and glycolysis happen in the cytoplasm, and photosynthesis occurs in plant cells' chloroplasts.

This sentence correctly uses a comma before "so" to connect two ideas. The other sentences have missing or incorrect punctuation.

The suffix "-ful" means "characterized by," so "graceful" means "characterized by grace."

This sentence presents a specific statistic that may not be common knowledge and is not the author's original idea, so it requires a citation to give credit to the source of this information. A citation is needed to show where this statistic came from, who conducted the study, and when it was conducted. Therefore, option C is the correct answer.

Choice B: "Whenever the boys played in the rain, they came home with muddy clothes."

This is a complex sentence. "Whenever the boys played in the rain" is a dependent clause because it cannot stand alone as a complete thought, and "they came home with muddy clothes" is an independent clause because it can stand alone. The sentence does not contain two independent clauses joined by a coordinating conjunction (which would make it a compound sentence).

Choice D: "She wanted to go to the beach after she left work."

This is also a complex sentence. "She wanted to go to the beach" is an independent clause, and "after she left work" is a dependent clause because it cannot stand alone as a complete sentence.

To clarify:

• Complex sentence: Contains an independent clause and at least one dependent clause.
• Compound sentence: Contains two independent clauses joined by a coordinating conjunction (like "and," "but," or "or").

Thus, both B and D are complex sentences, but B is the most accurate answer in many tests as it clearly demonstrates the use of a dependent clause ("Whenever the boys played in the rain") followed by an independent clause.

"The book" is the subject, and "is" correctly agrees with it. The other sentences have incorrect verb forms for their subjects.

The sentence " There were buffalo in every western territory of the United States as of 1860." requires citation because it presents a claim or fact that is not common knowledge and needs to be supported by a source

According to the rules of capitalization, the first letter of a sentence and proper nouns should be capitalized. In option D, "Rocky Mountains" is a proper noun and it is capitalized correctly. Geography is also a proper noun identifying a subject.

In option A, "College" should not be capitalized as it is a common noun.

In option B, it is partly correct however"Western" should be capitalized as it is a proper adjective referring to a specific region.

In option C, "A1 Plumbing Board of Directors" is capitalized correctly, but "range" should not be capitalized as it is a common noun.

Therefore, option D is the correct answer.

The ureter is a large tube that carries urine from the kidneys to the bladder. The other options are small (microscopic) parts of the kidney that help filter blood.

The given sentences present a logical sequence of events, starting with the dog and owner being asleep in their home, followed bythe intruder breaking into the house, the dog biting the intruder who was attacking the owner, and finally, the statement about the dog being a man's best friend.

This order creates a clear and coherent story.