Choose the best answer.(根据短文内容，选择最恰当的答案)

    Uncle Wang works in a book shop in the middle of the city. The shop is not far from his home. It is about one kilometre away. So Uncle Wang seldom goes to work by bus.  He usually goes there by bike, sometimes on foot. It takes him twenty minutes to get there by bike and forty minutes on foot. Today his bike is broken. He wants to walk there. Now he is having breakfast. He leaves home at ten minutes to eight and he walks to work twenty minutes earlier. His work starts at half past eight in the morning and finishes at a quarter to five in the afternoon.