All practice questions

The sentence below is about maritime archaeology. Which present-tense form of the verb 'allow' correctly completes the sentence to ensure proper subject-verb agreement?

Analyze the passage below to determine the correct form of the verb 'provide' that maintains tense consistency, and type the correct word in the blank.

The monumental Arch of Constantine, which stands near the Colosseum and features reliefs repurposed from earlier imperial monuments, celebrate the victory of Constantine I over Maxentius. Many modern historians analyze these architectural choices as deliberate political propaganda.

Which choice best completes the underlined portion of the sentence?

Although many of her colleagues found the research tedious, Marie Curie's dedication was more intense, more focused, and longer-lasting than any other scientist in her laboratory.

Which choice is the most effective and grammatically correct replacement for the underlined portion of the sentence?

In 1964, radio astronomers Arno Penzias and Robert Wilson began using a highly sensitive horn antenna to measure cosmic signals. They soon detected a persistent static buzz that interfered with their data. Hoping to eliminate the interference, they painstakingly cleaned the instrument. Ultimately, [this] proved to be the cosmic microwave background radiation, the first physical evidence of the Big Bang.

Which of the following choices best clarifies the reference of the underlined word in the passage?

In the 1940s, geneticist Barbara McClintock studied the inheritance patterns of maize. She discovered that certain genetic elements could change positions on a chromosome. Her colleagues initially dismissed these 'jumping genes' as anomalies, McClintock persisted in her research, eventually earning a Nobel Prize in 1983.

Which of the following choices is the most grammatically correct replacement for the underlined portion of the sentence?

For decades, deep-sea exploration was limited by the immense pressure of the ocean floor, which crushed standard submersibles. Although modern titanium-alloy hulls have enabled researchers to reach the Mariana Trench. This boundary-pushing technology has opened up new fields of marine biology.

Which choice best corrects the underlined portion of the passage?

During the restoration of the historic theater, the architect explained to the contractor and I that if you want to preserve the lobby's original plaster, one must ensure that its surface remains dry.

Which of the choices makes the underlined portion of the sentence grammatically correct?

Deep-focus earthquakes occur at depths of $300\text{ km}$ to $700\text{ km}$, where high temperatures and pressures are expected to cause mantle rocks to deform plastically rather than fracture. Two scientists propose different hypotheses to explain the initiation of these deep earthquakes.

Scientist 1
Deep-focus earthquakes are caused by *dehydration embrittlement*. Subducting tectonic plates carry hydrous minerals (such as serpentine) deep into the mantle. As temperature and pressure increase with depth, these minerals undergo dehydration reactions, releasing liquid water. This pressurized fluid fills microscopic pore spaces, reducing the effective normal stress on pre-existing faults. The reduction in friction allows the rock to suddenly slip, generating an earthquake.

Scientist 2
Deep-focus earthquakes are caused by *transformational plasticity*. The mantle mineral olivine ($\text{Mg}_2\text{SiO}_4$) undergoes a phase transition to a denser polymorph, wadsleyite, at a depth of approximately $410\text{ km}$. Within cold subducting slabs, this transition is delayed, creating a metastable region of olivine. Under high shear stress, small zones of metastable olivine undergo a rapid, runaway transformation into wadsleyite. This phase change weakens the shear strength of the rock along narrow shear zones, causing localized instability and sudden displacement.

Based on Scientist 1's hypothesis, which of the following conditions must be met for a deep-focus earthquake to occur at a depth of $500\text{ km}$?

The following passage is an excerpt from a science essay.

In 1915, Albert Einstein published his general theory of relativity, which revolutionized our understanding of space and time. He proposed that gravity is not a force in the traditional sense, but rather a curvature of spacetime caused by mass and energy. Although many physicists initially doubted these radical equations, subsequent observations of a solar eclipse in 1919 confirm his predictions.

Which option best maintains the consistent verb tense throughout the paragraph?

Exoplanet Atmosphere Models

Two scientists discuss the source of nitrogen ($N_2$) in the atmosphere of Kepler-186f, a newly discovered terrestrial exoplanet.

*Scientist 1*
The exoplanet's atmospheric nitrogen is entirely primordial, having been delivered by carbonaceous chondrite meteorites during planetary accretion $4.5$ billion years ago. The nitrogen was subsequently released into the atmosphere via early volcanic outgassing. Because the exoplanet's surface temperature has remained below $250\text{ K}$, there is no active tectonic recycling or geochemical process capable of returning nitrogen to the mantle or releasing new nitrogen from the crust. Thus, the total amount of nitrogen in the atmosphere has remained constant since the planet's formation.

*Scientist 2*
The exoplanet's atmospheric nitrogen is not primordial but is continuously replenished. Kepler-186f experiences ongoing tidal heating, keeping its mantle partially molten and driving active subduction zones. Nitrogen is continuously drawn into the mantle via plate tectonics and then released back into the atmosphere through arc volcanism. Furthermore, solar wind strip-mining slowly removes nitrogen from the upper atmosphere, meaning that without this active tectonic cycle, Kepler-186f would have lost its atmospheric nitrogen within $1$ billion years of formation.

Consider the following statement: According to Scientist 1, the volcanic outgassing of nitrogen on Kepler-186f occurred only during the early history of the planet and is not an ongoing process.

Based on the models provided, is this statement True or False?

A student is revising a draft about a recent engineering project. To ensure the sentence uses correct adjective and adverb forms, which words should fill the blanks to correctly modify the words in parentheses?

In 1877, Edgar Degas invited the American painter Mary Cassatt to exhibit her work with the Impressionists. Cassatt, who had grown frustrated with the rigid rules of the traditional French Salon, eagerly accepted the invitation. She began preparing a series of paintings featuring mothers and children, and [it] became a defining characteristic of her artistic legacy.

Which of the following alternatives to the underlined portion most clearly and precisely completes the sentence?

Complete the sentence comparing two planets by filling in the blanks with the correct comparative form of the adjective "large" and the correct comparison word.

### Mammoth Population Decline

Scientists debate the primary cause of the woolly mammoth’s extinction at the end of the Pleistocene epoch.

Hypothesis 1
The extinction was driven by rapid climate warming, which altered the vegetation of the mammoth's habitat. The dry, grassy steppe-tundra transitioned into wet, nutrient-poor shrublands and forests, which could not support the dietary needs of large herbivores like mammoths.

Hypothesis 2
The extinction was caused by human overhunting. As human populations expanded across northern regions, their advanced hunting tools and strategies allowed them to hunt mammoths at rates far exceeding the species' natural reproduction rates, driving them to extinction.

New Evidence
Researchers analyzed woolly mammoth fossils and plant pollen from sediment layers on a remote Siberian island. They found that a major decline in the mammoth population occurred over a $500$-year period during which grass pollen levels dropped by $80\%$ and shrub pollen levels increased. The earliest human artifacts on the island date to $1,000$ years after the mammoth population had already completely disappeared.

Based on this new evidence, which of the following statements best describes the impact of the findings on the two hypotheses?

In a study of reaction kinetics, a student investigates the reaction between sodium thiosulfate ($Na_2S_2O_3$) and hydrochloric acid ($HCl$). The reaction produces solid sulfur, which precipitates and clouds the solution.

Experiment 1
The student placed a beaker containing $50\text{ mL}$ of $0.1\text{ M}$ $Na_2S_2O_3$ over a sheet of paper marked with a black cross. The student then added $10\text{ mL}$ of $1.0\text{ M}$ $HCl$ to the beaker, immediately started a stopwatch, and recorded the time (in seconds) required for the liquid to become so opaque that the black cross was no longer visible. The reaction was conducted at $25^\circ\text{C}$. The student repeated this procedure at temperatures of $35^\circ\text{C}$, $45^\circ\text{C}$, and $55^\circ\text{C}$, keeping the volumes and concentrations of the reactants constant.

Suppose the student wants to design a follow-up experiment to determine how the concentration of $HCl$ affects the reaction rate, while ensuring that temperature does not act as a confounding variable. Which of the following modifications to the procedure of Experiment 1 would best achieve this goal?

The Roman Pantheon features a massive concrete dome that remains the largest unreinforced concrete dome in the world. Although modern engineers have analyzed the structure using advanced computer models. They still marvel at how the volcanic ash concrete has withstood seismic activity for nearly two millennia.

Which of the following choices best corrects the underlined portion of the passage?

Read the passage about Marie Curie's pioneering scientific work. What is the correct form of the verb 'conduct' that fills the blank to maintain a logical and consistent sequence of verb tenses in the passage?

In the late nineteenth century, inventor Jan Ernst Matzeliger revolutionized the footwear industry by designing the lasting machine. Hand-lasters could produce only about fifty pairs of shoes a day, however, the lasting machine could yield up to seven hundred. This dramatic increase in production efficiency significantly lowered the cost of footwear for consumers.

Which of the following options, if any, is the most effective replacement for the underlined portion?

The Venus flytrap is a carnivorous plant native to subtropical wetlands on the East Coast of the United States. It catches its prey—chiefly insects and arachnids—with a trapping structure formed by the terminal portion of each of the plant's leaves. When an insect touches the trigger hairs, the trap snaps shut, this happens in less than a second. This rapid movement relies on complex physiological changes, including sudden shifts in cell turgor pressure.

Which of the following choices is the best replacement for the underlined portion?