单项选择题
A．at most seventy B．at least seventy C．more or less seventy D．much more than seventy
A．The color of school buses is the same as other buses. B．All the schools have their own buses. C．The space among seats is large in order to make children feel comfortable. D．Most of school buses have seats placed quite close together.
A．cheap fare B．frequent travel C．speed D．directness