单项选择题
A. sent by telegraph B. sent by letter C. passed from one person to another D. sent by telephone
A. we fail to listen carefully when they talk B. people tend to be annoyed when we check what they say C. people usually state one thing but mean another D. we tend to doubt what our friends say
A. Mechanisms for safer navigation. B. The economic structure of the marketplace. C. A specific group of commodities. D. The advantages of lowering taxes.