Recent technological advancements in manned and unmanned undersea vehicles…
2025
Recent technological advancements in manned and unmanned undersea vehicles have overcome some of the limitations of divers' equipment. Without a vehicle, divers often became sluggish and their mental concentration was limited. Because of undersea pressure that affected their minds, concentration among divers was difficult or impossible. But today, most oceanographers make observations by means of instruments that are lowered into the ocean or from samples taken from the water. Direct observations of the ocean floor are made not only by the divers but also by deep-diving submarines. Some of these submarines can dive to depths of more than several miles and cruise at depths of 15 thousand feet. Radio-equipped buoys can be operated by remote control in order to transmit information back to land-based laboratories including data about water temperature, currents, and weather. Some of mankind's most serious problems, especially those concerning energy and food, may be solved with the help of observations made possible by these undersea vehicles.
How is a radio-equipped buoy most likely to be operated?
- A.
cannot be inferred
- B.
By operators inside the vehicle, underwater
- C.
By operators outside the vehicle on a diving platform
- D.
By operators outside the vehicle on a ship
Attempted by 1 students.
Show answer & explanation
Correct answer: D
An inference question in reading comprehension asks for the conclusion that the passage's stated facts logically support -- not a fact repeated word for word, and not a claim the passage never actually backs.
The passage explicitly says radio-equipped buoys 'can be operated by remote control.' This single detail already rules out any option that puts a human operator physically inside the buoy. The passage's entire point is that instruments, submarines, and buoys are technological substitutes for divers -- direct human diving is described as difficult and limited, which is exactly the difficulty that devices like these buoys overcome. An option that ties the buoy's operation back to a diving-specific setup reintroduces the very reliance on divers that the passage says buoys replace, so it does not fit. Among the choices offered, remote operation from a general-purpose surface vessel -- a ship -- rather than a diver's platform is the only option consistent with both 'remote control' and the passage's diver-independent framing.
"cannot be inferred" is wrong because the passage gives a specific detail ("operated by remote control") from which the operating arrangement can reasonably be inferred.
"By operators inside the vehicle, underwater" is wrong because "remote control" explicitly means the operator is not physically inside the buoy.
"By operators outside the vehicle on a diving platform" is wrong because it ties the buoy's operation back to a diving-specific setup, but the passage frames buoys (unlike divers) as devices that work by remote control precisely so that direct diver involvement is not needed.
By elimination, the buoy is most likely operated by remote control from a ship.