The other day,my brother drove his car down the street _.A at a speed of 40 km B at a speed 40 km

问题描述:

The other day,my brother drove his car down the street _.A at a speed of 40 km B at a speed 40 km
per hour

B spped of 不是时速
40km per hour 是时速B选项没有of也可以吗有of是错的表达