单项选择题
A．the practice of turning goods into money B．making goods available for purchase C．the customer-centered approach D．a form of persuasive salesmanship
A．he didn"t follow his teacher"s advice B．he was too poor to buy better paper to write on C．he regarded his writing on old newspaper just as a draft D．he was not used to the calligrapher"s teaching manner
A．for B．to C．on D．after