前两天，收到编辑部的修改意见，其中有条意见如下，请各位大虾帮我分析一下，他是要我干什么，特别是第二句话，我看的不是特别的明白。

Comments on your work have now been received. On this basis, your Editor is advising that you revise your manuscript.

（2）A portfolio of financial assets is considered in the empirical application, but there is no discussion of aggregating the portfolio to obtain portfolio returns. A discussion of this issue is essential for any application in empirical investment analysis.