The train (past)(passed) at a terrific speed.选哪个,为什么呢?

The train (past)(passed) at a terrific speed.选哪个,为什么呢? the train passed at a terrific speed The train traves at a speed of 80 kilometres per hour 向划线部分( The train passed. The train ＿＿＿ at the present speed until it reaches the foot The train ______ at the present speed until it reaches the f the train is moving at the speed of 120 miles per hour. at speed 还是at a speed At a fantastic speed train is travelling at a speed of 15m/s and slows down unifo at the speed of 和at a speed of的不同 speed不是不可数嘛,那么at a high speed 又怎么说呢、、、