GRE Sample Test 3 Verbal Reasoning 1

Questions 15 to 17 refer to the passage below.
For each question, select one answer choice, unless the instructions state otherwise.


The idea to use Navajo for secure communications came from Philip Johnston, the son of a missionary to the Navajos and one of the few non-Navajos who spoke their language fluently. Reared on the Navajo reservation, Johnston was a World War I veteran who knew of the
5 military’s search for a code that would withstand all attempts to decipher it. He also knew that Native American languages, notably Choctaw, had been used in World War I to encode messages.
Johnston believed Navajo answered the military requirement for an undecipherable code because it is an unwritten language of
10extreme complexity. Its syntax and tonal qualities, not to mention dialects, make it unintelligible to anyone without extensive exposure and training. It has no alphabet or symbols and is spoken only on the Navajo lands of the American Southwest. One estimate indicates that fewer than 30 non-Navajos, none of them Japanese, could understand
15the language at the outbreak of World War II.
Early in 1942, Johnston met with Major General Clayton B. Vogel, the commanding general of Amphibious Corps, Pacific Fleet, and his staff to convince them of the Navajo language’s value as code. Johnston staged tests under simulated combat conditions, demonstrating
20 that Navajos could encode, transmit and decode a three-line English message in 20 seconds. Machines of the time required 30 minutes to perform the same job. Convinced, Vogel recommended to the Commandant of the Marine Corps that the Marines recruit 200 Navajos.