Tüm alıştırma soruları

To avoid a dangling modifier, the introductory phrase must logically modify the subject of the clause that follows it. Complete the sentence by typing the correct phrase from the brackets: [the geologist published her findings, the findings of the geologist were published].

In a school election for student council president, the ratio of the number of votes received by Candidate A to the number of votes received by Candidate B was $2:3$. If Candidate B received $120$ votes, how many votes did Candidate A receive?

Each autumn, millions of monarch butterflies undertake a grueling multi-generational migration from North America to the oyamel fir forests of central Mexico. To survive this arduous journey, these delicate insects rely on thermal updrafts to chill out and cruise over long distances. Researchers studying this phenomenon have noted that the butterflies' navigation systems are remarkably precise, allowing them to return to the exact same groves year after year.

Which choice best maintains the established tone of the passage?

The committee members debated the proposal for hours. Ultimately, they failed to reach a consensus of opinion that they all agreed on.

Which of the following choices most effectively and concisely replaces the underlined portion of the passage?

To prepare for the upcoming track meet, the athlete practiced her sprints, worked on her breathing, and stretched daily. Which choice is the best version of the underlined portion?

The following passage is adapted from an article about agricultural history.

In the early twentieth century, botanist George Washington Carver recognized that intensive cotton farming was depleting the soil of vital nutrients. To address this issue, Carver advocated for crop rotation, urging farmers to plant nitrogen-fixing crops like peanuts and sweet potatoes. This practice not only replenished the soil but also provided farmers with a bunch of alternative sources of income. Carver's research eventually transformed Southern agriculture by promoting sustainable, diversified farming techniques.

Which of the following choices best replaces the bolded phrase a bunch of to maintain the formal, academic tone of the passage?

Green Sahara Transition

Approximately $5,000$ years ago, the Sahara region transitioned from a humid, vegetated grassland (the 'Green Sahara') into a hyper-arid desert. Two hypotheses discuss the cause of this rapid desertification:

Hypothesis 1 (Orbital-Monsoon Hypothesis)
The greening of the Sahara was sustained by high summer insolation due to Earth's orbital configuration. As Earth's precession cycle gradually changed over thousands of years, solar radiation decreased, weakening the monsoon. This gradual decline triggered a sudden vegetation-atmosphere feedback: less rain reduced vegetation, which increased albedo, further reducing rainfall and causing rapid desertification.

Hypothesis 2 (Human pastoralist Hypothesis)
Early human pastoralists introduced livestock to the region around $6,000$ years ago. Overgrazing removed vegetation, which increased surface albedo (reflectivity) and reduced evapotranspiration. This created a local cooling and drying effect that disrupted the monsoon cycle, driving the rapid shift to a desert state.

Match each new scientific finding with the hypothesis it supports and the reasoning behind it.

The mechanical engineer designed a lightweight, durable, gear, but the prototype failed during high-stress testing.

Which choice is the best version of the underlined portion of the sentence?

In the 1930s, archaeologist Tatiana Proskouriakoff traveled to Mayan ruins in Mexico and Guatemala to create architectural reconstructions. As she studied the stelae—carved stone slabs—she noticed patterns in the dates inscribed on them. Rather than depicting stories of gods as was previously believed, the monuments, she proposed, recorded the lives of historical rulers. This discovery revolutionized Mayan studies, as it [underlined]shifts[/underlined] the academic understanding of Mayan glyphs from abstract myths to historical records.

Which of the following is the best replacement for the underlined word 'shifts'?

### Models of the Permian-Triassic Extinction Event

The Permian-Triassic (P-Tr) extinction event, which occurred approximately $252\text{ million years ago}$, resulted in the loss of over $90\%$ of marine species. Geologists have proposed different models to explain the cause of this mass extinction.

Model 1 (Volcanic Outgassing Model)
This model proposes that the eruption of the Siberian Traps, a massive region of volcanic rock, released enormous volumes of carbon dioxide ($CO_2$) and methane ($CH_4$) into the atmosphere over a span of several hundred thousand years. This led to rapid global warming of approximately $10^\circ\text{C}$, causing severe ocean acidification. Warm oceans absorbed less oxygen, leading to widespread ocean anoxia (oxygen depletion), which suffocated marine life.

Model 2 (Bolide Impact Model)
This model proposes that a large asteroid or comet (bolide) collided with Earth at the P-Tr boundary. The impact vaporized target rocks containing anhydrite ($CaSO_4$), releasing massive quantities of sulfur dioxide ($SO_2$) into the stratosphere. This caused global cooling and severe acid rain. The subsequent collapse of land and ocean food webs led to massive organic decay, which depleted dissolved oxygen in the oceans, causing widespread marine anoxia.

Instruction:
Based on the models provided, match each description of an extinction trigger, mechanism, or timeline on the left with the model(s) on the right that it describes.

A chemical mixture is kept in a temperature-controlled chamber where the temperature $T$, in degrees Celsius, is restricted to the range $-10 \le T \le 10$. The mixture remains stable as long as the temperature satisfies the inequality:

What is the sum of all integer values of $T$ in this range for which the mixture is stable?

### The Faint Young Sun Paradox
During the Archean Eon, approximately $3.8$ to $2.5$ billion years ago, the Sun’s energy output was only about $70\%$ to $75\%$ of its present-day value. Under these conditions, the Earth should have been completely frozen, yet geological evidence indicates that liquid water and life were present. Scientists debate how Earth maintained a warm climate during this period.

Scientist 1
The early Earth was kept warm primarily by a super-greenhouse effect caused by extremely high levels of carbon dioxide ($CO_2$) and water vapor ($H_2O$). Volcanic outgassing released $CO_2$ at rates up to 100 times greater than today, building an atmosphere with $CO_2$ levels high enough to prevent global glaciation despite the weaker Sun.

Scientist 2
High $CO_2$ levels alone could not have prevented glaciation because geochemical evidence from ancient soils limits Archean $CO_2$ concentrations to levels too low to explain the warmth. Instead, the primary driver of warming was methane ($CH_4$) produced by early anaerobic microbes. This methane, in combination with moderate $CO_2$ levels, formed a powerful greenhouse gas mixture that prevented freezing.

Scientist 3
Earth’s temperature was maintained not by an enhanced greenhouse effect, but by a lower planetary albedo (reflectivity). The Archean Earth had much smaller continental landmasses and lacked land plants, meaning less sunlight was reflected back into space. Additionally, fewer biological cloud condensation nuclei existed, resulting in fewer, larger cloud droplets that reflected less solar radiation.

Based on the passage, which of the following statements best describes the core claim of Scientist 2 regarding the prevention of global glaciation during the Archean Eon?

A baker is preparing a recipe that calls for $2$ times the sum of $\frac{1}{4}$ cup of milk and $\frac{2}{5}$ cup of water. What is the total volume, in cups, of these two liquid ingredients combined?

What is the value of the expression below?

Read the following passage:

Marine archaeologists recently explored the ruins of a seventeenth-century merchant ship off the Greek coast. Undisturbed on the seafloor for centuries, the divers mapped the wreckage carefully. They hoped to uncover clues about ancient Mediterranean trade routes.

Which of the following options represents the most grammatically correct revision of the underlined portion?

Read the passage below. Which word most precisely and clearly completes the sentence to maintain the formal, academic register of the passage?

The passage below is from a historical report about the discovery of mauveine, the first synthetic dye. Read the passage and write the correct form of the verb 'leave' that fits the blank while maintaining consistent verb tense throughout the paragraph.

A baker makes a fruit tart using strawberries and blueberries. The ratio of the number of strawberries to the number of blueberries used in the tart is $3:5$. If the baker uses a total of $40$ berries to make the tart, how many strawberries are used?

Recent studies in forest ecology demonstrate that peatlands play a vital role in carbon sequestration, storing more carbon than all other vegetation types combined. When these wetlands are drained for agriculture, they release vast quantities of greenhouse gases. To prevent this degradation, conservationists are working to restore natural water levels, which is a super awesome way to mitigate global climate change.

Which choice best maintains the style and tone established in the passage?

What is the sum of all integer values of $y$ that satisfy the inequality $|2y - 3| \le 7$?