在A+2B→2C的反应中，若32g物质A和足量物质B恰好完全反应，生成56g物质C，则参加反应的物质B的质量为　____ ．若 A的相对分子质量为32，则B的相对分子质量为　____ ．

    Hello! I'm Linda. I have a good e-friend. Her name is Zhang Yun. Her English name is Betty. She is a Chinese girl, but she lives in the UK with her parents. Her father is a doctor and her mother is a teacher. She is ten years old. She call me big sister. She is good at English. She likes Chinese and I also like Chinese. She likes singing and playing basketball. This is my good e-friend. Do you want to know more?

根据句意及汉语提示完成句子。