案例分析题 （70）处应填写（）

单项选择题Since 1870, Americans have witnessed（）.

A．a dramatic change in American service system
B．a great change in the daily life of Americans
C．an increase of supermarkets
D．a great increase in the number of experienced people in the production of services

单项选择题（69）处应填写（）

A．cover
B．cure
C．recover
D．heal