All practice questions

Submarine atmospheric control systems utilize electrolytic oxygen generators as their primary method to sustain breathable air during extended submerged deployments. In enclosed undersea vessels, ambient oxygen is continuously consumed by the crew while carbon dioxide accumulates. Rather than carrying hazardous reserves of compressed oxygen tanks that occupy vital hull space, the onboard generation unit uses electrical currents to split purified seawater into breathable oxygen gas and byproduct hydrogen, which is safely vented overboard. Consequently, electrolytic oxygen generators provide the essential life-support capability required for submarines to remain submerged for months at a time.

Which of the following statements best expresses the main idea of the passage?

Read the sentence below and determine the core base word of the emboldened term after removing all prefixes and suffixes. What is the base word of nonperishable?

During field operations, tactical combat casualty care units deploy reverse osmosis water purification units (ROWPU) to treat brackish groundwater. Before contaminated intake water reaches the high-pressure pump, a dual-stage multimedia filter removes suspended particulate matter exceeding 25 microns. The fluid is then injected with sodium hexametaphosphate at a concentration of 4 parts per million to prevent mineral scale accumulation along the spiral-wound polyamide membranes. Operating at a sustained manifold pressure of 800 pounds per square inch, the system produces 600 gallons of potable water per hour while discharging concentrated brine. To prevent biological fouling during downtime, operators flush the assembly with a 2 percent citric acid solution.

According to the passage, what specific chemical and concentration are added to inhibit mineral scale buildup on the membranes?

Before winter flights, ground crews must inspect aircraft wings for ice, snow, or frost accumulation, which disrupts airflow and reduces lift. Technicians apply a heated glycol-based de-icing fluid to melt existing frozen contaminants, followed by an anti-icing fluid designed to temporarily prevent new ice from forming before takeoff. This two-step process ensures the aerodynamic surfaces remain smooth and capable of generating sufficient lift during departure. Regular adherence to these procedures is essential for maintaining flight safety in freezing weather conditions.

Which of the following statements best summarizes the passage?

The supervisor was careful during the briefing so that no technician would misconstrue the instructions. What does the word misconstrue most nearly mean?

Read the historical passage carefully. Then, fill in the blanks to complete the sentence that best synthesizes the author's implicit main idea.

Read the following technical report summary and fill in the blanks with the exact details provided in the passage:

During sea trials of high-efficiency gas turbine propulsion units, naval technicians observed that secondary intercoolers reduce overall compression work only when intake temperatures exceed 45°C. Under cooler operating conditions, the bypass valve diverts pressurized air directly into the recuperator to prevent thermal shock across the turbine rotor blades. Standard service schedules require lubrication filter replacements every 300 operating hours, whereas the ceramic thermal barrier coatings on combustion chamber liners are inspected strictly at 1,200 operating hours to check for micro-fracturing.

A contractor is installing a decorative border around a newly built rectangular patio. The patio is $15$ feet long and $10$ feet wide. If the border material costs $\$2$ per foot, what is the total cost of the material needed?

To safely inspect and replace a vehicle's spark plugs, a technician must first disconnect the negative battery cable to eliminate the risk of electrical shock. Next, any debris surrounding the spark plug boot should be cleared with compressed air before removing the ignition coil. After unscrewing the old spark plug, the technician must verify the electrode gap on the replacement plug. Finally, the new spark plug is threaded into the cylinder head by hand before being torqued to manufacturer specifications.

According to the passage, which action should be taken immediately before removing the ignition coil?

Read the passage below:

Portable reverse osmosis water purification units allow field personnel to produce drinkable water from contaminated freshwater sources. The process begins when raw surface water is drawn through an intake strainer to block large debris like twigs and gravel. Next, the water passes through a multimedia sediment filter to eliminate suspended silt and fine turbidity. A high-pressure pump then forces the clarified water through semipermeable membranes that trap microscopic pathogens and dissolved minerals. Finally, small amounts of chlorine are injected into the treated water to prevent bacterial regrowth during storage and distribution.

Based on the passage, arrange the key steps of the water purification process in the correct chronological order from first to last.

When dissimilar metals are immersed in an electrolyte such as seawater, galvanic corrosion rapidly degrades the more chemically active metal. To prevent destructive corrosion on vital steel hulls and bronze propeller shafts, marine vessels utilize sacrificial zinc anodes. Zinc possesses a lower electrochemical potential than steel and bronze, causing it to oxidize preferentially. As the zinc anode corrodes over time, it generates a protective electron flow toward the surrounding cathodic structure, preserving the integrity of the vessel's primary components. Consequently, routine drydock inspections focus heavily on measuring anode depletion rates to ensure continuous corrosion defense.

Which of the following best describes the author's primary purpose in this passage?

Read each short passage below. Match each passage with the unstated central claim (implicit main idea) it best supports.

Read the following passage about deep-sea submersibles:

Deep-sea research submersibles operating in hadal trenches rely on two distinct structural strategies to withstand extreme hydrostatic load while maintaining neutral buoyancy. For crew accommodation, engineers utilize grade-5 titanium spherical pressure hulls, as spherical geometry distributes crushing isotropic forces evenly across the hull wall, eliminating localized shear points. Conversely, vehicle flotation cannot use trapped atmospheric air; instead, submersibles incorporate solid syntactic foam blocks composed of microscopic hollow glass microspheres embedded within rigid epoxy resin. This composite material resists high-pressure compaction while providing vital uplift because its aggregate density remains significantly lighter than surrounding seawater. Furthermore, external structural frames are fabricated from open-matrix syntactic composites that allow ambient water to flood internal voids, preventing differential pressure accumulation across chassis components.

Based on the passage, match each factual detail from the text with its accurate paraphrased restatement.

Passage:
Naval degaussing systems reduce a warship's magnetic signature to prevent the detonation of underwater magnetic influence mines. By routing controlled direct electrical current through a network of heavy copper coils installed throughout the ship's hull, these systems generate an opposing magnetic field that neutralizes the vessel's permanent and induced magnetization. Modern installations continuously adjust coil currents based on real-time readings from onboard triaxial magnetometer sensors, compensating for changes in geographic latitude and ship orientation. While this magnetic masking does not protect against acoustic or visual tracking methods, it significantly diminishes the vulnerability of surface combatants navigating shallow littoral minefields.

Statement: The primary purpose of naval degaussing systems is to neutralize a ship's magnetic field to protect it against underwater magnetic mines.

Match each uppercase vocabulary term with its exact direct synonym. Which pairings correctly associate each word with its corresponding meaning?

The lead instructor had to temper his demanding training regimen to prevent excessive physical fatigue among the trainees. What is the meaning of the underlined word in this sentence?

The factory supervisor addressed the staff to resolve the growing discontentment among the assembly crew. What is the base word of discontentment?

Read the passage below:

Synthetic webbing slings used in shipboard cargo handling must be inspected prior to each lift for signs of ultraviolet degradation, broken stitching, or chemical exposure. Unlike steel wire ropes, synthetic fibers can fail abruptly without visible stretching if damaged by acid vapors or excessive heat. Immediate removal from service is mandatory whenever any core yarns become visible.

Statement: The author's primary purpose in this passage is to emphasize the necessity of inspecting synthetic cargo slings for safety hazards before use.

A facility management team is filling a newly constructed rectangular water holding tank for the base fire department. The tank's interior measures $30$ feet long, $15$ feet wide, and $10$ feet deep. For safety regulations, the tank must only be filled to $80\%$ of its total capacity. If the water pump delivers $600$ cubic feet of water per hour, how many hours will it take to reach the required fill level?

Each sentence below contains a vocabulary word alongside an embedded context clue. Match each sentence to the definition that corresponds to its underlined word.