Businesses
问题Businesses have also been engaging in a type of electronic commerce , （）occurs when one b
Businesseshavealsobeenengaginginatypeofelectroniccommerce,（）occurswhenonebusinesstransmi
问题（）, businesses offer services for which they charge a fee that is based on the number of
（）,businessesofferservicesforwhichtheychargeafeethatisbasedonthenumberofsizeoftransactio