What's the problem sir?You (were driving) at least at a speed of about 100 miles per hour.
问题描述：
What's the problem sir?You (were driving) at least at a speed of about 100 miles per hour.
为什么不是have been driving
答
先生,这是怎么啦?你（驾驶）,至少在大约每小时100英里的速度.
have been driving (grammar 是错的）意思也不对.意思是‘一直在’
You were driving = 你刚才开车
What's the problem?通常在问的时候语气是不太好的,正式的解释是 ‘怎么啦’ 而不是 有什么问题.