1.那架飞机正以每小时500英里的速度飞行。【误】The airplane is flying with a speed of500m iles an hour.【正】The airplane is flying ata speed of500m iles an hour.【析】名词speed作“速度”、“速率”解时,既可作可数名词又可作不可数名词用;作“快速”、“迅速”解时,总是用作不可数名词。汉语“以高速”,在英语中习惯上说atspeed。speed前面用with,表示的速度概念较模糊,例如:with speed,with allspeed,with greatspeed等。speed前面用at,表示较具体的速度,或者表示极端的对比速度。例如:atfullspeed,athigh speed,attop speed,atlow speed,atordinary speed,ata speed of...等。例如:1)They were m arching on with allspeed.他们正全速前进。2)The plane flies ata top speed of660m iles an hour...