一幅图的（ ）和（ ）的比，叫做这幅图的比例尺。
图上距离；实际距离
275. A telephone is an instrument by which we can speak to people far away. The underlined word means ____.
A．a tool
B．an experiment
C．an expression
D．an instruction
（）
A．黄山
B．栖霞山
C．雁荡山
D．武当山
