Tüm alıştırma soruları

Bakers around the world prize sourdough for its complex flavor and airy texture. Unlike commercial bread made with isolated yeast strains, the cultivation of traditional sourdough starters, which relies on a symbiotic culture of wild yeast and lactic acid bacteria, require patience and precise temperature control. A baker must feed the starter daily to maintain its vitality.

Which of the following choices correctly completes the underlined portion of the sentence to maintain proper subject-verb agreement?

An environmental microbiologist studying soil ecology estimates the average volume of a single soil bacterium to be $2.0 \times 10^{-12}$ cubic centimeters ($\text{cm}^3$). What is the average volume of this bacterium expressed in cubic micrometers ($\mu\text{m}^3$)?

### Supercooled Water Phase Behavior

When liquid water is cooled below its freezing point ($0^\circ\text{C}$) without solidifying, it is considered supercooled. As the temperature of supercooled water decreases, several of its thermodynamic properties, such as isothermal compressibility and isobaric heat capacity, increase rapidly. Two physicists propose conflicting hypotheses regarding the physical behavior of supercooled water at extremely low temperatures and high pressures.

Physicist 1
Water possesses a second critical point—a liquid-liquid critical point (LLCP)—located in the deeply supercooled region at low temperatures and high pressures. Below this critical temperature, supercooled water exists as a mixture of two distinct liquid phases: Low-Density Liquid (LDL) and High-Density Liquid (HDL). The rapid rise in thermodynamic properties observed as water is supercooled is due to critical fluctuations associated with this LLCP. As temperature decreases at ambient pressure, the liquid water is attracted toward this critical point, causing its fluctuations to grow, but the liquid inevitably crystallizes into ice before the LLCP can be reached directly.

Physicist 2
There is no second critical point. The anomalous increases in compressibility and heat capacity do not indicate a phase transition between two liquids. Instead, these anomalies are the continuous, singularity-free behavior of a single, highly hydrogen-bonded network. As water is supercooled, the formation of local, low-density tetrahedral structures increases continuously. This cooperative bonding behavior causes the thermodynamic properties to increase progressively down to a minimum temperature, below which they must decrease again. The apparent divergence of these properties is a mathematical artifact of extrapolating data from temperatures where crystallization is avoided; there is no physical boundary or critical point separating two liquid states.

According to the passage, Physicist 2's explanation of supercooled water differs from Physicist 1's explanation because Physicist 2 claims that supercooled water:

In a biochemistry laboratory experiment, a microfluidic device is calibrated to pump an enzyme solution into a reaction chamber at a constant rate of $4.8 \times 10^{-5}$ liters per minute ($\text{L/min}$). What is this pump rate in microliters per second ($\mu\text{L/s}$)?

In 1903, Mary Anderson observed a New York streetcar driver struggling to see through sleet. She quickly designed a hand-operated squeegee to clear the windshield, manufacturing companies rejected her invention as a distraction to drivers.

Which of the following options represents the most grammatically correct and logical version of the underlined portion of the sentence?

The following passage contains an underlined portion.

Astrophysicists use gravitational lensing to map the distribution of dark matter in distant galaxy clusters. When light from a background galaxy passes near a massive foreground cluster, the cluster’s gravity acts like a giant lens. This bends and distorts the light into arcs and multiple images, consequently, these cosmic mirages reveal the total mass of the lens, including both visible stars and invisible dark matter. By analyzing the distortions, researchers can construct detailed dark matter maps.

Which option best replaces the underlined portion to ensure the sentence is grammatically correct?

Meteorologists use weather balloons to gather data from the upper atmosphere. These balloons carry instruments called radiosondes high into the sky, they measure temperature, humidity, and pressure. This valuable information is then transmitted back to ground stations for analysis.

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

### Seasonal Antarctic Ozone Decrease

Two scientists present opposing viewpoints on the primary cause of the seasonal decrease in stratospheric ozone ($O_3$) concentration over Antarctica.

Scientist 1

The seasonal decrease in stratospheric ozone over Antarctica is primarily caused by chemical reactions involving chlorine-containing compounds, specifically chlorofluorocarbons (CFCs). During the dark polar winter, polar stratospheric clouds (PSCs) form. Chemical reactions on the surfaces of PSC ice crystals convert inactive reservoir species of chlorine into highly reactive forms, such as chlorine gas ($Cl_2$). In the spring, sunlight returns and photolyzes these molecules, releasing free chlorine atoms ($Cl$). These chlorine atoms act as catalysts, rapidly destroying ozone molecules in a cycle that requires sunlight. Therefore, the ozone hole is a direct result of anthropogenic chemical emissions.

Scientist 2

The seasonal ozone decrease is primarily a dynamic meteorological phenomenon caused by atmospheric wind patterns and temperature changes, rather than chemical destruction. During winter, a strong polar vortex isolates the air mass over Antarctica, preventing warmer, ozone-rich air from lower latitudes from mixing with polar air. Because the stratosphere over Antarctica gets extremely cold, the air descends, which naturally compresses and thins the ozone layer. Additionally, periodic increases in solar activity release high-energy particles that produce nitrogen oxides ($NO_x$) in the upper atmosphere. These nitrogen oxides naturally destroy ozone when they descend into the stratosphere. Thus, the seasonal ozone minimum is driven by natural cycles of solar radiation and atmospheric dynamics.

Scientist 1 and Scientist 2 differ in their views regarding which of the following points?

A student conducts an experiment to investigate how the concentration of hydrochloric acid ($\text{HCl}$) affects the rate of chemical reaction with calcium carbonate ($CaCO_3$). The experimental conditions for the four trials are shown in the table below:

Which of the following is the primary confounding variable in this experiment that prevents the student from drawing a valid conclusion about the effect of acid concentration?

Designed by the legendary architect Julia Morgan, nearly three decades were spent constructing Casa Grande, the main building of the Hearst Castle estate.

Which of the following versions of the underlined portion results in the most logical and grammatically correct sentence?

The passage below describes a challenge in botanical research. Which present-tense form of the verb 'to require' correctly completes the sentence to maintain proper subject-verb agreement?

In the sixteenth century, Dutch cartographers revolutionized mapmaking by incorporating mathematical projections to represent the curved Earth on flat paper. Which allowed sailors to navigate long-distance ocean voyages with unprecedented accuracy. This advancement fundamentally changed global exploration and trade.

Which of the following choices is the best edit for the underlined portion of the sentence?

In scientific experiments, failing to control variables or using improper measurement techniques can introduce errors. Match each experimental scenario with the primary source of error or confounding variable it introduces.

An environmental scientist is writing a report on a wetland field study. Arrange the following segments to construct a grammatically correct sentence that maintains a parallel structure.

The following passage contains an underlined portion.

Bioluminescent fungi grow on decaying wood in damp forests around the world. These organisms emit a soft green glow known as foxfire. This light attracts nocturnal insects, they help disperse the fungus's spores.

Which of the following options best replaces the underlined portion to make the sentence grammatically correct?

Neither of the two prototype drones has their navigation system fully calibrated for night flights.

Which of the following options is the correct replacement for the underlined portion of the sentence?

Two geologists present opposing hypotheses regarding the formation of the Channeled Scablands, a region of deeply eroded channels in eastern Washington.

Geologist 1
The Channeled Scablands were carved rapidly by a sudden, catastrophic deluge. A massive glacial ice dam holding back Lake Missoula failed, releasing approximately $2,000 \text{ km}^3$ of water in a few days. This high-velocity flood eroded basaltic bedrock into deep coulees and left behind giant current ripples—gravel bars up to $15 \text{ m}$ high. The erratic boulders found throughout the region were transported rapidly by this fast-moving water.

Geologist 2
The Channeled Scablands were formed gradually over millions of years. Meltwater streams flowing along ice sheet margins during multiple glacial cycles slowly eroded the basalt bedrock. No catastrophic flood occurred. The giant gravel formations are actually ancient sand dunes deposited and shaped by wind over long periods, and the erratic boulders were deposited directly by moving glaciers.

Match each scientific claim regarding the features of the Channeled Scablands to the geologist whose hypothesis it supports.

Read the sentence below and fill in the blank with the pronoun that correctly agrees with its antecedent.

### Origin of Earth's Water

How Earth acquired its water remains a subject of active scientific debate. Three scientists present different hypotheses regarding the source and timing of water delivery to the early Earth.

Scientist 1
Earth formed in a region of the solar nebula that was too hot for water vapor to condense. Consequently, the proto-Earth was initially dry. Earth’s water was delivered late in the accretion process, specifically during a "late veneer" phase after the Moon-forming impact. This water was carried by carbonaceous chondrite asteroids originating from the outer solar system, which were rich in hydrated minerals. The isotopic ratio of deuterium to hydrogen ($D/H$) in Earth's oceans closely matches that of these carbonaceous chondrites, confirming they are the primary source.

Scientist 2
Earth's water is primordial, meaning it was incorporated while the planet was still growing in the presence of the solar nebula. As the proto-Earth grew, its gravity captured a dense, hydrogen-rich nebular atmosphere. This hydrogen dissolved directly into the molten magma ocean. Once dissolved, the hydrogen reacted with iron oxides ($FeO$) in the magma, producing water ($H_2O$) and metallic iron ($Fe$). The iron sank to form the core, leaving the synthesized water in the mantle. Therefore, Earth's water was synthesized *in situ* prior to the Moon-forming impact, and no late-stage outer solar system bombardment was necessary.

Scientist 3
Earth's water was not delivered by asteroids, nor was it synthesized in a surface magma ocean. Instead, hydrogen gas was trapped inside the iron-rich core during the initial separation of the core and mantle. Over geological time, this hydrogen has steadily diffused upward into the lower mantle. In the mantle, the hydrogen reacts with silicate minerals under high-pressure conditions to synthesize water molecules. This deep-mantle water is slowly transported to the surface via mantle plumes and volcanic outgassing. This ongoing chemical synthesis is the primary contributor to Earth's surface water.

Which of the following statements best describes the core hypothesis of Scientist 3 regarding the origin and delivery of Earth's surface water?

The sentence below contains a dangling modifier error because the action in the introductory phrase is not performed by the subject that immediately follows it. Read the sentence and select the phrasing from the list below that correctly completes the sentence. Which phrasing should be filled in the blank to ensure the modifier is placed correctly?

List of options:
- a detailed timeline of prehistoric atmospheric changes was reconstructed by the climatologist
- it was possible for the climatologist to reconstruct a detailed timeline of prehistoric atmospheric changes
- the climatologist reconstructed a detailed timeline of prehistoric atmospheric changes
- the reconstruction of a detailed timeline of prehistoric atmospheric changes was completed by the climatologist