at a speed单独用没有of是什么意思?

at a speed单独用没有of是什么意思? 用at the speed of造句 急用! at the speed of 和at a speed of的不同RT! at high speed 还是at a high speed,教材上是前一种两者区别是什么? The train traves at a speed of 80 kilometres per hour 向划线部分(at a speed向at a speed of 80 kilometres per hour 提问 spread at a fast speed?介词用什么?at? at a speed of和 at a rate of有区别吗 冠词能用the吗 对at the speed of提问,应用What's the speed of还是How fast ,区别是什么? light travels at a speed which is about a million times faster than the speed of sound The car was seen travelling at a speed of 150km/h shortly .为什么此句用travelling呢. travel at half the speed of light The other day,my brother drove his car down the street _.A at a speed of 40 km B at a speed 40 kmper hour ar top speed为什么不说at a top speed at the rate of =at the speed of a motoboat travelling at full speed against the current goes 14miles an hour.travelling at a half speed with the current goes 10miles an hour .find the rate of the current and the maximum speed of the boat Every Sunday,hundreds of cars and buses p____ through the village at a very high speed. 翻译we are travelling at a speed of 90 kilometers an hour. 英语翻译The high speed of air travel is gained at a cost.