Kevin And His Stamp Album

My brother's name is Kevin.He likes to collect stamps.He has collect stamps for four years.He has ten stamp albums.He has 3,000 stamps.They are from Australia, Japan, Taiwan, theUSA, theUK,Turkey and many different countrys.
He 's always showing his stamps to his classmate.He takes the magnifying grass to his friends,and he uses tweezer to take the stamps.He has many penpals.They are exchanging stamps.so,he has different country's stamps.
Where does he get them?He usually go to the post office to buy them,and exchange with friends.I want to collect stamps with him next month.