阅读短文，填空。

    A bus stopped at the bus stop. A young woman got on the bus with her son. They sat down next to the window. The conductor(售票员) came to them for the tickets. The young mother said，"One ticket to the People's Park." The conductor looked at the little boy and asked, "How tall are you?" The mother wanted to say something, but the conductor stopped her. The little boy said loudly(大声地)，"Mom tells me I'm 1.2 metres tall at home and 1.08 metres tall on the bus. " All the other passengers(乘客)on the bus laughed.