- A student is revising an explanatory paragraph about chemical reactions. The teacher requires no contractions and an objective tone. Which revision best meets those expectations?
Original: "In a chemical reaction, atoms rearrange to form new substances, and you can tell it is happening because there is usually a color change or gas bubbles."
Answer: In a chemical reaction, atoms rearrange to form new substances, and observers can often identify evidence such as color change, temperature change, or gas production.
The teacher asked for two things: no contractions and an objective tone. An objective, formal explanation keeps the focus on the topic instead of speaking directly to the reader. The best revision replaces "you can tell" with "observers can often identify," which shifts to a neutral third-person viewpoint, and it names precise evidence: color change, temperature change, or gas production. That combination meets both requirements.
The option about changes being "pretty obvious to anyone watching" stays in second person ("you can tell") and uses vague, subjective wording instead of objective language. The option comparing the reaction to substances "turning into something totally different" relies on a loose, informal comparison rather than precise explanatory detail, and it also keeps the second-person "you." The option ending with "there are bubbles and other signs" breaks the no-contractions rule ("it's") and stays casual and imprecise. Only the revision using "observers can often identify" keeps a consistent, objective, contraction-free style throughout.
- A student wrote two versions of an explanatory sentence for a health class about sleep. Which version better maintains a formal explanatory style appropriate for an informational essay?
Version 1: "Sleep is super important because it helps your brain sort stuff out, and you will feel way better the next day."
Version 2: "Sleep supports cognitive functioning by assisting memory consolidation and other restorative processes that occur during the night."
Answer: Version 2, because its precise domain vocabulary and objective tone present the information formally and informatively for the reader.
Formal explanatory writing keeps the focus on information rather than on the writer's feelings or the reader. The best answer is Version 2 because it uses precise, subject-specific vocabulary and an objective tone that presents facts without emotion.
The choice praising Version 1's emotional wording and direct address is wrong because explanatory writing informs rather than persuades through feeling, and phrasing like "you will feel" breaks the objective stance a formal essay needs.
The choice claiming Version 1's casual vocabulary is clearer is wrong because phrases like "super important" and "sort stuff out" are vague, while Version 2's technical terms are actually more exact.
The choice calling both versions equally formal is wrong because sharing a topic and using complete sentences does not make two sentences equal in register—Version 1's slang and conversational tone are clearly less formal than Version 2's academic style.
- A student is writing an explanatory paragraph about plate tectonics. The paragraph begins formally but shifts in style:
"Plate tectonics describes the movement of large sections of Earth's lithosphere over the asthenosphere. This movement is driven primarily by convection currents in the mantle and results in features such as mid-ocean ridges and mountain ranges. But like, it is basically just giant rock plates sliding around, which is wild."
Which revision best maintains a consistent formal explanatory style while keeping the meaning?
Answer: Plate tectonics involves the movement of lithospheric plates, which can interact to form geologic features such as ridges, trenches, and mountain ranges.
The correct revision keeps the same objective, technical voice as the formal opening: it names "lithospheric plates" and describes the "geologic features such as ridges, trenches, and mountain ranges" that form, presenting information neutrally with no opinion or emotion. Each other option opens with identical precise vocabulary, so you cannot pick by scanning for technical words—you have to judge the tone all the way through. The option that says geologists study how "the surprising forces beneath our feet reshape the world" slips into evaluative, informal language ("surprising," "beneath our feet") that breaks the neutral register. The option calling the features "among the most fascinating on the planet" shifts from explaining facts to expressing an opinion about how interesting the topic is. The option describing "nature's powerful and unpredictable forces" adds dramatic, emotional wording rather than stating information objectively. Only the keyed choice sustains both accurate terminology AND a fact-focused, neutral voice from start to finish. In formal explanatory writing, you must maintain precise vocabulary and an objective tone together—technical terms alone are not enough if the sentence also carries evaluation or emotion.
- A student is writing an explanatory paragraph about why coastal areas often have milder temperatures than inland areas. Which sentence would be least appropriate for a formal explanatory style?
Answer: It's pretty nice how the ocean sort of keeps the weather from getting too crazy for everybody living nearby along the coast.
The task is to find the sentence that does not fit a formal explanatory style. The sentence about water heating and cooling slowly stays formal: it uses precise verbs like "moderate" and keeps an objective, third-person tone. The sentence about smaller temperature ranges also fits, using neutral wording and an academic transition even though its phrasing is a bit plain. The sentence about sea breezes stays formal too, relying on the technical term "sea breezes" and describing a cause-and-effect process without personal comment. The correct choice is the one saying it's "pretty nice how the ocean sort of keeps the weather from getting too crazy." This one breaks formal style in several ways at once: "pretty nice" states a personal opinion instead of a fact, "sort of" is vague hedging that weakens the explanation, and "too crazy" is slang rather than precise language like "extreme." Because it combines casual, conversational, and opinion-based wording, it is the least appropriate choice for a formal explanatory paragraph.
- A student is checking whether the style of an informational paragraph is appropriate. Read the paragraph:
"The respiratory system supplies oxygen to the body and removes carbon dioxide. Air enters through the nose or mouth, travels down the trachea, and moves into the lungs. In the alveoli, oxygen diffuses into the bloodstream while carbon dioxide diffuses out. This exchange supports cellular respiration."
Is the style appropriate for formal explanatory writing for a science class?
Answer: Yes, because it stays in third person, chooses precise vocabulary, and keeps an objective tone while explaining the process clearly.
The paragraph does exactly what formal explanatory writing calls for, so the best answer is the one saying the style is appropriate because it stays in third person, uses precise vocabulary, and keeps an objective tone. Every sentence focuses on the topic rather than on a narrator, and terms like "trachea," "alveoli," and "diffuses" are the correct, precise words for a science explanation.
The choice claiming each technical term must be defined the instant it appears is wrong: formal explanatory writing may use accurate domain vocabulary without pausing to define every word, so the term use here is a strength, not a flaw.
The choice claiming the writer should add a personal reason the topic matters is wrong: formal explanatory writing keeps an objective focus on the process and avoids personal appeals to the reader.
The choice claiming the sentences should be shorter and simpler is wrong: combining related steps into a clear complex sentence ("oxygen diffuses into the bloodstream while carbon dioxide diffuses out") is appropriate and effective for explanatory writing. Because all three criteria in the correct answer are met, only that choice fits.
- A student is revising an explanatory paragraph about the Underground Railroad. The draft reads:
"The Underground Railroad was a bunch of secret routes and safe places that helped enslaved people escape. People were really brave, and it is crazy to think about how they did it. They did not have a lot of stuff, but they kept going anyway."
Which revision best establishes a formal explanatory style while keeping the main ideas?
Answer: The Underground Railroad was a network of secret routes and safe houses that assisted enslaved people in escaping to free states and Canada. Participants faced serious risks and relied on careful planning, limited resources, and cooperation.
The best revision keeps a formal explanatory style from start to finish. It uses precise, academic vocabulary ("network," "safe houses," "assisted," "participants," "limited resources"), stays in an objective third-person point of view, and reports the facts in complete sentences without opinions or slang. It also keeps every main idea: what the Underground Railroad was, the risks people faced, and their lack of resources.
The other choices keep casual or personal language that does not fit a formal explanation. One recycles the draft's informal words—"a bunch," "really brave," "a lot of stuff," "crazy," and "pulled it off"—so it reads like conversation, not explanation. Another opens with "I am going to tell you about," which is first person and announces the topic instead of objectively presenting it, and it still uses "a bunch" and "a lot of stuff." The last one is the most conversational of all, using fillers and slang like "like," "honestly wild," "super brave," and "pull the whole thing off." Because a formal explanatory style requires objective tone, precise vocabulary, and no slang or personal commentary, only the first revision fully qualifies.
- A student must revise a mixed-style explanation about how vaccines help the immune system. The draft reads:
"Vaccines stimulate the immune system by introducing an antigen that does not cause the disease. Immune cells respond by producing antibodies and forming memory cells. Then, if the real germ shows up later, the body is ready to fight it off, which is pretty awesome."
Which revision best removes the informal element while preserving the explanatory purpose?
Answer: Vaccines stimulate the immune system by introducing an antigen that does not cause the disease; as a result, immune cells produce antibodies and memory cells that support a faster response to future exposure.
The best revision keeps a formal, objective explanatory style from start to finish. It uses precise, domain-specific vocabulary (antigen, antibodies, memory cells, future exposure), stays in third person focused on the topic, and links cause and effect with 'as a result.' Nothing is casual or emotional.
One option looks technical but shifts to a second-person address ('your body') and adds the emotional judgment 'remarkable' and the casual phrase 'show up later on,' which breaks the objective tone the task asks you to maintain.
Another option opens formally but inserts the first-person opinion 'I think' along with vague, informal wording ('basically ready,' 'somehow'), and opinion and vagueness do not belong in objective explanatory writing.
A third option carries the correct science but ends with the slang 'crush the real germ' and the emotional comment 'which is amazing,' replacing neutral, precise language with casual reaction.
Only the keyed revision removes every informal element while still explaining how vaccines work, so it is the single best answer.
- A student is writing an informational paragraph for a science class about earthquakes. Read the draft below.
"I am going to explain earthquakes. They happen when tectonic plates kind of crash into each other, and then the ground shakes a lot. It is pretty scary, and you can totally see why people freak out. Earthquakes cannot be predicted perfectly, but scientists try to use seismographs and stuff to figure out what is going on."
Which choice best identifies why this draft is too informal for formal explanatory writing?
Answer: The main problem is the writer's personal framing, casual words such as "kind of," "pretty," "totally," and "stuff," and emotional wording that pulls attention away from an objective explanation of the topic.
The best answer points to the writer's personal framing ("I am going to explain"), the casual words ("kind of," "pretty," "totally," "stuff"), and the emotional wording ("pretty scary," "people freak out"). These features make the writing sound conversational and center the writer's feelings instead of the topic, which is what breaks a formal, objective style.
The choice about specialized vocabulary is wrong because "tectonic plates" and "seismographs" are the exact, correct terms for this subject; precise technical words belong in explanatory writing and do not make it informal.
The choice about sentence variety is wrong because mixing short and long sentences is normal, effective writing; formal style does not require every sentence to be the same length, so this is not the flaw.
The choice about organization is wrong because explaining causes and effects is exactly what an informational paragraph should do; turning the topic into a story would not fix the informal tone, so organization is not the issue.
- A student is revising an explanatory paragraph about renewable and nonrenewable resources. The draft contains several informal elements:
"Nonrenewable resources are things like coal and oil, and once we use them up, they are gone. Renewable resources are stuff like wind and sunlight, and they keep coming back. I am going to be honest: fossil fuels are a huge problem, and it is really bad."
Which choice best identifies two features that make the style too informal for an explanatory essay?
Answer: The casual words such as "things" and "stuff" and the personal phrase "I am going to be honest."
The correct choice names two features that break a formal explanatory style. The vague words "things" and "stuff" are too imprecise for academic writing, where terms like "resources" or "energy sources" belong. The phrase "I am going to be honest" is a first-person aside that shifts from objective explanation to personal commentary, breaking the neutral tone an essay needs.
The choice about "coal" and "oil" and their definitions is wrong because naming specific terms and defining them is exactly what strong explanatory writing should do—these are strengths, not informal errors.
The choice about short, simple sentences and repeated "and" points to real features of the draft, but sentence length is not what makes the tone informal; formal writing can use short sentences, and simply connecting ideas with "and" is a style issue, not a register problem the question asks about.
The choice about wind, sunlight, and the energy topic is wrong because concrete examples and a clear topic focus are appropriate and helpful in explanatory writing—they do not lower the formality.
Only one choice identifies two genuine markers of informal register: imprecise casual vocabulary and a personal interjection.
- A student writes the following explanation for an 8th-grade health class:
"Dehydration happens when the body loses more water than it takes in. Symptoms can include dizziness, dry mouth, and fatigue. You should drink water before you feel thirsty because it is super important, and you do not want to feel awful."
Which element makes the style less appropriate for a formal informational explanation?
Answer: The phrase "super important" and the emotional wording "you do not want to feel awful" are informal and subjective for this paragraph.
The first two sentences keep a formal, objective tone: they focus on the topic in third person and use precise terms like "dehydration" and "symptoms." The last sentence breaks that style with the casual intensifier "super important" and the emotional appeal "you do not want to feel awful," which shift from stating facts to expressing feelings—so identifying those informal, subjective phrases is correct.
The choice about complete sentences and a third-person opening is wrong because those features actually create the formal, objective voice explanatory writing needs, not an audience problem. The choice about "dehydration" and "symptoms" is wrong because accurate technical vocabulary strengthens an explanation rather than weakening its clarity. The choice about the definition is wrong because defining a key term is a standard, expected feature of informational writing, not something limited to arguments. Only one option names an element that truly damages formal explanatory style.
- A student is revising a paragraph for an informational essay about renewable energy. The draft includes this sentence:
"Wind turbines generate electricity when moving air spins the blades, but they cannot work if there is no wind, so they are not always reliable."
Which revision best maintains a formal, objective explanatory style while improving precision?
Answer: Wind turbines generate electricity when wind turns the blades connected to a generator; however, output decreases when wind speeds are low.
The best revision keeps the focus on the technology, uses precise domain vocabulary, and states the limitation as an objective fact: it explains that the blades are "connected to a generator" and that "output decreases when wind speeds are low." This is more accurate than saying turbines simply stop working, and it stays neutral and third-person throughout.
The option using "generate power" and "kind of unreliable" loses precision by hedging casually and labeling the turbines with a vague, subjective judgment instead of describing what actually happens.
The option calling turbines "impressive machines" that "unfortunately cannot" work adds emotional, evaluative language ("impressive," "unfortunately") that does not belong in objective explanatory writing.
The option beginning "I think" and adding "in my opinion" and "probably" shifts into first-person opinion and uncertainty, which is inappropriate for presenting factual information.
Only the keyed revision maintains a formal, objective tone while making the description more exact, so it is the single best answer.
- A student is revising a technical explanation about how a lever works. The draft reads:
"A lever is a simple machine that helps you lift stuff. You put the thing you want to lift on one side, and you push down on the other side, and it makes it easier. It is basically like a seesaw."
Which revision best improves the draft to a formal explanatory style (objective, precise vocabulary, complete sentences, no contractions)?
Answer: A lever is a simple machine consisting of a rigid bar that pivots on a fulcrum; applying force to one side of the fulcrum can move a load on the other side by providing mechanical advantage.
The best revision keeps a third-person, objective focus and uses precise technical vocabulary throughout—'simple machine,' 'rigid bar,' 'fulcrum,' 'applying force,' 'load,' and 'mechanical advantage.' It presents the information neutrally as fact, with complete, sophisticated sentences and no contractions or casual words. That combination fully meets the formal explanatory style the stem asks for.
The option beginning 'A lever is a rigid bar that pivots on a fulcrum, and you can push down...' starts with technical terms but slips into second person ('you') and the casual word 'stuff,' breaking the objective, precise register.
The option beginning 'I will explain how a lever works' uses correct terminology but announces itself in first person ('I will explain'), which is a subjective, conversational move that a formal explanation avoids.
The option beginning 'A lever is a kind of rigid bar...' also uses technical terms but adds the vague hedge 'a kind of' and the subjective, emotional phrasing 'a really clever setup' and 'feel much easier,' which is opinionated rather than objective.
Only one revision stays fully formal—objective point of view, precise vocabulary, and neutral tone from start to finish.
- A student is writing an explanatory response for social studies about the system of checks and balances. Read the excerpt:
"The United States government separates power among the legislative, executive, and judicial branches. Each branch can limit the power of the others through specific constitutional responsibilities. For example, Congress passes laws, the President can veto legislation, and the Supreme Court can declare laws unconstitutional. Anyway, that is how they keep everybody from getting too bossy."
Which option best identifies the informal element that makes the style less appropriate for explanatory writing?
Answer: The phrase "Anyway," because it creates a conversational aside that reduces the formality expected in explanatory writing.
The excerpt keeps a formal explanatory style through most of the passage: it uses third-person focus, precise civic vocabulary, and complete sentences that state the process factually. The style slips only in the final sentence. The word "Anyway" works like a casual conversational aside, the kind of transition you would use in speech, not in academic writing, so it lowers the formality of the response. That is why naming "Anyway" is the best answer.
The choice about the concrete example is wrong because well-chosen examples, like vetoes and court rulings, actually strengthen explanatory writing rather than making it casual. The choice about "unconstitutional" is wrong because precise technical vocabulary is expected in formal explanatory writing and keeps the tone objective, not too advanced. The choice about describing the three branches is wrong because explaining each branch in a clear sentence supports the formal purpose and does not make the tone personal. Only the conversational aside "Anyway" actually breaks the formal style, so it is the informal element the question asks you to find.
- A student is revising a social studies explanation about how a bill becomes a law. The current draft says:
"I am going to tell you how a bill becomes a law. First, it gets introduced, and then it goes to a bunch of committees. If they like it, it moves on, and it is basically a long process."
Which revision best maintains a formal explanatory style (third person, objective tone, precise vocabulary, complete sentences, no contractions)?
Answer: The process by which a bill becomes law begins with its introduction in a legislative chamber and continues through committee review and additional votes before final approval.
The best revision keeps the focus on the topic rather than the writer and reports the process with precise governmental terms: a bill "begins with its introduction in a legislative chamber and continues through committee review and additional votes before final approval." This reads as objective, informative writing built from exact process vocabulary.
The revision about a bill going "through a bunch of committees, which is basically a pretty long and complicated journey" stays in third person but relies on casual, vague wording instead of precise legislative terms, so its tone is not formal.
The revision that says people "talk it over in committees and then decide together whether the idea is good enough" describes people and their opinions rather than the objective steps of the process, and its loose phrasing keeps the tone conversational.
The revision in which a lawmaker "suggests an idea" and "everyone in government finally agrees to sign off on the whole thing" reads smoothly but uses everyday expressions instead of accurate process terminology, so it also stays informal.
Only one choice sustains an objective tone and exact vocabulary throughout, so it is the best answer.
- A student is revising an informational explanation about how convection works in Earth's mantle. The draft says:
"Convection currents happen when hot material rises and cool material sinks. It is like when you heat soup and the stuff moves around. You can see it, and it is kind of wild."
Which set of changes would best improve the paragraph's formal explanatory style?
Answer: Remove casual comparisons and slang, and replace them with objective, specific phrasing that explains the process without personal opinion.
Formal explanatory writing keeps the focus on the topic, uses precise language, and stays objective. The draft weakens all three: "stuff" is vague, the soup comparison is casual, and "kind of wild" states a personal reaction instead of information. The best revision removes the casual comparisons and slang and replaces them with objective, specific phrasing that explains the process without opinion—exactly what a formal explanation needs.
Keeping the soup comparison and adding reactions like "I love watching it happen" makes the writing more informal and opinion-based, moving it further from a formal style. Trading technical terms for general words like "things" and "movement" removes the precise, domain-specific vocabulary that formal explanations depend on, so it lowers accuracy rather than improving style. Rewriting in the first person shifts attention to the writer instead of the process; formal explanations use an objective, third-person perspective, so this change also increases informality. Only removing the casual and subjective elements and replacing them with precise, neutral phrasing produces the formal explanatory style the question asks for.
- A student is deciding whether a draft is appropriate for an explanatory writing assignment about erosion. Read the draft:
"Erosion is the process that moves weathered rock and soil from one place to another. Water, wind, ice, and gravity can transport sediment, gradually changing Earth's surface over time. I have seen this happen at my cousin's house after storms, and it is crazy how fast the ground can disappear."
Which assessment is most accurate about the draft's style for an informational/explanatory purpose?
Answer: The draft is mostly formal at first, but the personal anecdote and emotional word choice reduce the objective explanatory tone.
The best answer says the draft starts formal but loses its objective tone at the end. The first two sentences explain erosion in third person with precise terms like "weathered rock," "sediment," and "transport." The last sentence breaks that style: "I have seen this happen at my cousin's house" shifts to a personal story, and "it is crazy how fast" adds casual, emotional language. That mix is exactly why the draft is only partly appropriate.
The choice claiming the personal example always strengthens the writing is wrong—personal anecdotes pull the focus away from objectively explaining the process, so they weaken formal explanatory tone here.
The choice calling terms like "sediment" too formal is wrong—precise, domain-specific vocabulary is exactly what explanatory writing should use, so those words are a strength, not a flaw.
The choice saying explanatory writing needs first person and personal voice is wrong—formal explanations usually stay in third person and objective, so the opening sentences are correct rather than a problem.
- A student is revising an explanatory paragraph about the water cycle for an academic audience. The draft includes informal language:
"So, the water cycle is basically how water moves around. Water heats up and then it goes up into the air, and later it comes back down. It is kind of like nature is recycling water over and over."
Which revision best maintains a formal explanatory style (third person, objective tone, precise vocabulary, complete sentences, no contractions) while keeping the meaning?
Answer: The water cycle describes the continuous movement of water through evaporation, condensation, and precipitation, which transfers water between Earth's surface and the atmosphere.
The best revision states the process objectively and uses precise scientific vocabulary: it names "evaporation, condensation, and precipitation" and describes water being transferred between "Earth's surface and the atmosphere." This keeps a third-person, informative tone with no opinion or vague wording, which is exactly what a formal explanatory style requires.
The choice calling the cycle "a fascinating natural process" with "amazing stages" injects emotional, evaluative language that does not belong in objective explanatory writing. The choice describing water that "rises upward into the sky" and "falls back down toward the ground" stays vague and everyday rather than using the correct technical terms, so it does not sound academic. The choice saying water "comes back down as it goes around and keeps working in this way" relies on loose, conversational phrasing instead of precise vocabulary. Each of these keeps the general meaning but fails to maintain the precise, objective, academic style the question asks for.
- A student is asked to evaluate style appropriateness for an informational essay. Read the excerpt below about renewable energy.
"Solar panels convert sunlight into electricity through photovoltaic cells. When light strikes the cells, electrons move through the material, creating an electric current. This process reduces reliance on fossil fuels and can decrease greenhouse gas emissions."
Is the style of this excerpt appropriate for formal explanatory writing?
Answer: Yes; it keeps a third-person, objective tone and relies on precise domain vocabulary to explain the process clearly for its readers.
The best answer says the style is appropriate because the excerpt keeps a third-person, objective tone and uses precise domain vocabulary—"photovoltaic cells," "electric current," "greenhouse gas emissions"—to explain the process accurately. That combination is exactly what formal explanatory writing requires.
The choice that wants the technical vocabulary swapped for first-person personal statements is wrong: formal explanations rely on that precise vocabulary and avoid the writer's personal intrusion, so removing it would weaken the writing.
The choice demanding emotional, persuasive language is wrong because explanatory writing informs readers neutrally rather than trying to persuade them to feel a certain way; the detached tone is a strength here, not a flaw.
The choice claiming the passage succeeds because of relaxed word choices and everyday phrasing misreads the text—the excerpt actually uses formal, technical language with no casual wording, so this reasoning credits a quality the passage does not have.
Only one choice correctly matches the excerpt's real features to the demands of formal explanatory style.
- A student wrote an informational explanation about erosion:
"Erosion is the movement of rock and soil by wind, water, ice, or gravity. Over time, erosion can shape landforms such as valleys and deltas. It cannot be stopped completely, but it can be reduced through practices such as planting vegetation to hold soil in place."
Which statement best evaluates the style of this explanation for a formal school assignment?
Answer: The style is appropriate because it stays objective, uses precise terms, and avoids informal language throughout the passage.
The best answer says the style works because it stays objective, uses exact terms, and avoids informal language. Formal explanatory writing keeps the focus on the topic and defines ideas neutrally, using accurate words like "erosion" and "landforms"—exactly what this passage does.
The choice that wants the writer to add a personal view about whether erosion helps or harms people is wrong: a formal explanation reports information neutrally and leaves out opinion.
The choice that calls the writing too reserved and asks for livelier, more conversational language is wrong: a chatty, informal tone is the opposite of what a formal school assignment calls for.
The choice that praises the passage for plain everyday wording and avoiding technical vocabulary is wrong on two counts—the passage clearly uses technical terms like "erosion" and "deltas," and formal writing depends on that precise vocabulary rather than avoiding it.
Only one choice correctly matches the passage to the standards of formal explanatory style.
- A student is writing an informational paragraph for a science class about earthquakes. Read the draft excerpt:
"Earthquakes occur when stress builds along a fault until the rocks suddenly slip, releasing energy as seismic waves. But honestly, it is kind of scary, and you can totally feel the ground do weird stuff. I think the worst part is how it happens out of nowhere."
Which choice best identifies what weakens the formal explanatory style of this excerpt (third person, objective tone, precise vocabulary, complete sentences, no contractions)?
Answer: The excerpt includes subjective and conversational language, such as "honestly," "kind of," "totally," and "I think," which shifts away from an objective explanatory tone.
The excerpt starts strong: "Earthquakes occur when stress builds along a fault... releasing energy as seismic waves" keeps a third-person, objective tone with precise science terms. Then it breaks down. Words like "honestly," "kind of," "totally," and "I think" turn the passage into casual, personal reaction instead of neutral information. That is the choice about subjective and conversational language, and it correctly names why the formal style collapses.
The choice about domain-specific terms is wrong because "fault" and "seismic waves" are exactly the precise vocabulary formal explanatory writing wants; replacing them would weaken the style, not strengthen it.
The choice about mixed verb tenses misreads the passage: "occur" and "slip" are both present tense, so tense is consistent and is not the problem.
The choice about one long compound sentence is wrong because explanatory writing can and does use complex sentences; sentence length is not what damages the tone here. The real weakness is register, not structure or vocabulary.
