<Tr> <Td> X </Td> <Td> Cross </Td> <Td> Al - an - as - dzoh </Td> <Td> Ałnáʼázdzoh </Td> </Tr> <Tr> <Td> Y </Td> <Td> Yucca </Td> <Td> Tsah - as - zih </Td> <Td> Tsáʼásziʼ </Td> </Tr> <Tr> <Td> Z </Td> <Td> Zinc </Td> <Td> Besh - do - gliz </Td> <Td> Béésh dootłʼizh </Td> </Tr> <P> Philip Johnston, a civil engineer for the city of Los Angeles, proposed the use of Navajo to the United States Marine Corps at the beginning of World War II . Johnston, a World War I veteran, was raised on the Navajo reservation as the son of a missionary to the Navajo . He was one of the few non-Navajo who spoke the language fluently . </P>

What two traits made the navajo language a good choice for a secret code