Data Validation

Hello,

I have a data validation list on cell A2:A11,what i want is not to display the duplicate values (such as apple & oranges
twice) in the list without changing the values in the validation table..is it possible..second thing is when i check apple
on A2 only chile and Poland should appear on B2 and the blank when i open the list should be avoided without changing the validation
list..third-thing is to get the ref# no on c3 on condition if apple matches chile then Ref should be 000011..

Please check the attached file for further ref

Thanks In Advance,
Ak