Which of the following sentences is written correctly?

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.

These prefixes mean "not" or "opposite of." "Mis-" means "wrongly" (like in "misunderstand"), so it does not fit.

Option C is most likely to be found in an email from a professor to her biology students at a college because it contains specific information related to the class schedule and activities. It mentions the research groups from a specific class meeting time, and gives a location where they should meet, which suggests it is a message intended for students in that class. Options A, B, and D are more likely to be found in casual conversations or in other types of messages not directly related to the biology class.

The word that defines "subterranean" based on the prefix "sub-" is B. Underground.

Choice A: In this option, the subject "The boys and girl" is a compound subject that includes both "boys" and "girl." The mistake here lies in the verb "is," which is singular. Since the subject is plural due to the presence of "boys," the correct verb should be "are."

Choice B: This choice correctly follows subject-verb agreement rules. The subject "The boy" is singular, so the verb "come" is appropriately singular. Similarly, for "the girls," which is plural, the verb "come" is used in its plural form.

Choice C: Here, the subject "The boys" and "the girls" are connected by "or," indicating a singular choice. However, the verb "sings" is in the singular form, which is incorrect for plural subjects. To maintain agreement, the correct verb should be "sing."

Choice D: In this option, the compound subject "The boys and girl" is again presented. However, the verb "visits" is singular, not in agreement with the plural subject. To ensure proper subject-verb agreement, the verb "visit" should be used.

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

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.

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.

1, 3, 4, 2, 5.

This order beginspresents the initial experiments, thenthe discovery, after which it discusses the research project,introduces the beliefand ends with the classification. While it provides the context for the belief, it starts with the discovery, which may confuse the reader as it doesn't establish the topic first.

The paragraph is as follows:

"Initially, we constructed experiments that explored new relationships among six major systems of the human body: circulatory, digestive, muscular, nervous, reproductive, and respiratory. Then, we discovered, through a series of curious events and calculations, that these systems were all intricately involved in a kind of psychic economy. Our experimental research project has focused on what we call the Psycho-Physical Performance Scale. We believe that this work will revolutionize our understanding of human behavior. Therefore, we ultimately chose to classify different triggers of human actions and productions according to these new relationships."

A topic sentence is the main idea or point of a paragraph. It serves as a guide to the reader, telling them what the paragraph is going to be about. A topic sentence should be clear, concise, and focused on a single idea, and it should summarize the main point of the paragraph. Therefore, the correct answer is A.