San Marino's postage stamps, which are valid for mail posted in the country, are mostly sold to philatelists and are an important source of income.
Selling postage stamps is an important source of income, too.
Selling postage stamps is an important source of income, too.
この文をもっと簡単に書き直してください: San Marino's postage stamps, which are valid for mail posted in the country, are mostly sold to philatelists and are an important source of income. 出力: