Why does the professor mention VISA and American Express?-刷...
题目问：教授提及VISA和American Express的目的是什么?教授在提到VISA和American Express前说道：“The other kind of credit card is issued by a credit company. (另一种信用卡是由信用公司发行的。)”后面又直接提到这两者是“examples of credit companies(信用公司的例子)”，故选择B项。