I spent an hour (in) washing cars/the car/my car.
It took me an hour to wash cars/the car/my car .
It cost an hour to wash cars/the car/my car.
以上三种都可以望采纳.
I spent an hour (in) washing cars/the car/my car.
It took me an hour to wash cars/the car/my car .
It cost an hour to wash cars/the car/my car.
以上三种都可以望采纳.