Execution Plan suggests adding all non key columns in the Create INCLUDE

Hello,

SQL Sertver 2008 R2 EP is suggesting to create a composite index with INCLUDE all columns.

I have some  basic understanding on INCLUDE when creating an index.

I have 70 some columns and  need to return all columns( on a report) and I have something like WHERE A = 'x' and B= 'Y'  and have tried creating a composite index ..of (A,b) but SQL Server does not use it  and is saying that 

Missing Index ( Impact 73) create a non clustered index (A,B) and is listing to include all columns 

I need to display all 70 some columns and may be that's why SQL Server is asking to include all columns by creating a composite index

Any suggestions? 

Thanks