IF customer does more than 50,000businessTHEN IF the customer wasn't in debt to us the last 3 monthsTHEN discount is15%ELSE(wasindebttous)IF customerhas been with us for more than 20 yearsTHENdiscountis10%ELSE (20 years or less) SO discount is 5%ELSE (customer does 50,000 or less) SO discount is nil结构化英语清华大学出版社清华大学出版社 IF customer does more than 50,000 business THEN IF the customer wasn’t in debt to us the last 3 months THEN discount is 15% ELSE ( was in debt to us) IF customer has been with us for more than 20 years THEN discount is 10% ELSE ( 20 years or less) SO discount is 5% ELSE ( customer does 50,000 or less) SO discount is nil 结构化英语