表示路程的s是英文单词speed；表示速度的v是英文单词velocity。

speed的英式读法是[spid]；美式读法是[spid]。作名词时意思是速度；迅速。作动词时意思是加速；急行。

例句：

They were travelling at a speed that was double the legal limit.

他们正以两倍于法定限速的速度行驶。

The police are advising motorists to reduce speed because of the fog.

由于有雾，警察告诫驾车者减慢速度。