OG详解-OG6 文法 Q27

Choice C is the best answer. The sentence emphasizes a similarity between the Choctaw Code Talkers and the Navajo Code Talkers by explaining that both groups used their native languages to transmit coded messages for the military.
Choice A is incorrect. The sentence describes the Choctaw Code Talkers; it doesn’t emphasize a similarity between the Choctaw Code Talkers and the Navajo Code Talkers. Choice B is incorrect. The sentence introduces the Navajo Code Talkers; it doesn’t emphasize a similarity between the Choctaw Code Talkers and the Navajo Code Talkers. Choice D is incorrect. The sentence emphasizes a difference between the Choctaw Code Talkers and the Navajo Code Talkers; it doesn’t emphasize a similarity.