text: SELECT PC.model, PC.price FROM PC JOIN Product ON PC.model=Product.model WHERE Product.maker='B'
  UNION
  SELECT Laptop.model, Laptop.price FROM Laptop JOIN Product ON Laptop.model=Product.model WHERE Product.maker='B'
  UNION
  SELECT Printer.model, Printer.price FROM Printer JOIN Product ON Printer.model=Product.model WHERE Product.maker='B'
  