YOU MUST have been driving at seventy miles an hour.这里去掉AT可以

YOU MUST have been driving at seventy miles an hour.这里去掉AT可以 You must have been driving at seventy miles an/per hour. you must have been driving at seventy miles an hour为什么要用ing You must have been driving at seven miles an hour "You needn't drive at seventy miles an hour. I overtook you at eight miles an hour这句话对吗 高三语法题:情态动词---You were driving at 100km an hour.---But office The car ran at 100 miles an hour.中文意思, Have you been to an aquarium ever可以去掉吗? And later the train was ____ at seventy kilometers an hour.A She has to drive at seventy miles that day 改错 The train was travelling at a good sixty miles an hour.good