I would appreciate it you call back this afternoon for the doctor’s appointment.
A. until
B. if
C. when
D. that
网友回答
A. until
(答案→)B. if
C. when
D. that
解析:考查连词:A. until直到B. if 如果C. when当…时候D. that引导从句,固定句型:appreciate it if…,如果…我会很感激的,it是形式宾语,if后面是从句,句意:如果今天下午你打回电话来赴医生的约会我会很感激的。选B。