sed to match only exact string only in all occurences

Dear Friends,

Anybody knows how to match exact lines only in multilinear.

Input file:

apple
orange
orange
apple
apple
orange

Desired output:
fruit
orange
apple
fruit

i used the command

 
s/fruit\norange/fruit\
/

Only the exact match with correct order should match..

Can anybody have answer?

Vasanth

---------- Post updated at 02:09 AM ---------- Previous update was at 02:08 AM ----------

sorry comand used is

s/apple\norange/fruit\
/

sed 'N;s/apple\norange/fruit/' infile