补全对话根据对话内容，在空白处写出恰当的句子，使对话意思连贯完整。所写句子应与所给的标点符号一致。
A：51.【1】？
B：Yes，please.I want to order a birthday cake for my mother.
A：52.【2】？
B：A large cake，please.
A：53.【3】？
B：Please write “Happy Birthday to Mother”on it.
A：OK.54.【4】？
B：It's 66375688.
A：55.【5】？
B：No.56 Zhenxin Road.
【答案】【1】Can I help you?
【2】What size would you like?
【3】What do you want to write on it?
【4】What’s your phone number?
【5】What’s your address?
【解析】这是订生日蛋糕的一组对话。
【1】根据Yes，please.I want to order a birthday cake for my mother.可知是和售货员的对话，售货员应该说需要我帮忙吗；故填Can I help you?
【2】根据A large cake，please.可知是问要多大尺寸的；故填What size would you like?
【3】根据Please write “Happy Birthday to Mother”on it.可知问在上面写什么；故填What do you want to write on it?
【4】根据It's 66375688. 可知问电话号码是什么；故填What’s your phone number?
【5】根据No.56 Zhenxin Road.可知是问地址；故填What’s your address?