单项选择题
A. He must take a connected flight at Jacksonville. B. He has to change the flight at Albany. C. He will fly for two hours. D. He will fly directly to his destination.
A. They don’t need conventional signs and symbols. B. They only require a receiver in communication. C. The distance between communicators can’t be too long. D. They are not restricted in time and space.
A. The adoption of modern ideologies can stop war. B. The adoption of any ideology could prevent war. C. The adoption of some ideologies could prevent war. D. The adoption of any ideology can’t stop war.