1) Initially, we constructed experiments that explored new relationships among six major systems of the human body: circulatory, digestive, muscular, nervous, reproductive, and respiratory.

2) We believe that this work will revolutionize our understanding of human behavior.

3) Then, we discovered, through a series of curious events and calculations, that these systems were all intricately involved in a kind of psychic economy.

4) Our experimental research project has focused on what we call the Psycho-Physical Performance Scale.

5) Therefore, we ultimately chose to classify different triggers of human actions and productions according to these new relationships.

Which of the following best orders these sentences to form a well-organized paragraph?

Checking for spelling is a step in the proofreading process. Proofreading involves reviewing a written document for errors and making corrections as necessary. This can include checking for spelling errors, grammar mistakes, punctuation errors, and formatting issues.

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

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 correct use of "fewer" and "less" is important in proper grammar and usage. "Fewer" is used when referring to items that can be counted, while "less" is used for quantities that cannot be counted. In this case, "people" is a countable noun, so "fewer" is the correct word to use. Additionally, "effect" is the correct noun to use in this sentence, as it refers to the result or consequence of the action, while "affect" is a verb meaning to influence or have an impact on.

This sentence is spelled correctly. The other choices have mistakes: "hear" instead of "here," "price" instead of "prize," and "harestyles" instead of "hairstyles."

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 commas correctly set off "or jiaozi," which is an extra detail. The other sentences either need a comma for direct address, have comma splices, or have incorrect punctuation.

The concluding sentence of a paragraph serves to sum up the main idea or point that has been discussed in the paragraph. It provides closure to the paragraph and helps transition to the next one. Therefore, the correct answer is B.

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.

A complex sentence is one that contains an independent clause and at least one dependent clause.

In Choice C: "Since time was running short, I hurriedly brushed my teeth while breakfast was warming up," we have an independent clause: "I hurriedly brushed my teeth," and a dependent clause: "Since time was running short." The dependent clause cannot stand alone as a complete sentence, so it depends on the independent clause for its meaning. This combination of an independent and dependent clause makes Choice C a complex sentence.

The other choices are not complex sentences because they either lack a dependent clause or do not have the same level of complexity in their structure.