题目

在A+3B=2C+2D中，A和B的相对分子质量之比为9：11,已知1.8gA与一定量B恰好完全反应，生成5.1gD，则在此反应中B和C的质量比为                    （    ） A.2：1        B.3：4         C.12：11         D.1：1 答案：A －I just heard that the tickets for tonight's show had been sold out． －Oh no!________． [　　] A．I was looking forward to that B．It doesn't matter C．I knew it already D．It's not all interesting