Everyday items like potatoes, bread, onions, and even saliva are the tools of art conservators, who work to clean and restore works of art. Which of the following is misspelled in the sentence above?

Correct Answer: A

Rationale: The correct spelling is 'potatoes,' with the correct plural form being used in this context. The other choices are spelled correctly: 'saliva,' 'conservators,' and 'restore.' 'Saliva' refers to a bodily fluid, 'conservators' are professionals who work on art conservation, and 'restore' means to bring something back to its original condition or state.

Correct Answer: B

Rationale: The misspelled word in the sentence is 'astronemers,' which should be spelled as 'astronomers.' 'Astrophysicists,' 'techniques,' and 'technology' are all correctly spelled words in the sentence. Ensuring proper spelling is essential for effective communication and clarity. The term 'astronomers' refers to individuals who study celestial bodies, including stars, making it the correct answer in this context.

Correct Answer: D

Rationale: The correct plural form of 'potato' is 'potatoes.' In English, most plural nouns form by adding '-es' or simply '-s' to the singular form. Therefore, 'potatoes' is the correctly formed plural noun in this list. The other choices, 'vertebrae,' 'geese,' and 'octopuses,' are the correct plural forms of 'vertebra,' 'goose,' and 'octopus,' respectively. They demonstrate the common rule of adding '-es' or '-s' to form plural nouns.

Correct Answer: C

Rationale: A complex sentence has one independent clause and at least one dependent clause connected by a subordinating conjunction or a relative pronoun. In choice C, the sentence 'Because the distance between stars in the galaxy is far greater than the distance between planets' is a dependent clause introduced by the subordinating conjunction 'Because,' while the rest of the sentence 'interstellar travel is expected to be an even bigger challenge than interplanetary exploration' forms the independent clause. This combination of an independent clause and a dependent clause makes choice C a complex sentence. Choices A, B, and D do not contain both an independent and dependent clause connected in the way that choice C does, thus they do not qualify as complex sentences.

Correct Answer: D

Rationale: The statement that 'Heat engines can be broken down into combustion and non-combustion engines' is correct. Heat engines can indeed be categorized into combustion engines, where fuel combustion occurs, and non-combustion engines, such as steam engines, where heat is applied without combustion. This categorization helps in understanding the different mechanisms and types of heat engines available. Choices A, B, and C are incorrect. Choice A is incorrect as heat engines are not the most common type of engine; internal combustion engines are more prevalent. Choice B is incorrect as pneumatic and hydraulic motors are not types of electric engines, but rather different systems that use gas (pneumatic) or liquid (hydraulic) to transmit power. Choice C is incorrect as it lists electric engines, which are not a primary classification of engines like heat engines, but rather a type of engine that uses electricity to operate.