It is a common practice in the USA that one needs to make a(n) _ before seeing a doctor.A

问题补充：

It is a common practice in the USA that one needs to make a(n) _ before seeing a doctor.

A. difference

B. impression

C. appointment

D. decision

答案：

A. difference

B. impression

(答案→)C. appointment

D. decision

解析：句意：在美国看医生之前需要预约是常规惯例。make an appointment约定，预约。所以选C。