问题补充:
Having seen the X-ray, the doctor decided to the patient.
A. operate
B. operate on
C. work
D. work on
答案:
A. operate
(答案→)B. operate on
C. work
D. work on
解析:考查动词和动词短语:A.operate操作,经营,B. operate on给…做手术,C.work工作, D.work on从事,句意:看过X光后,医生决定给病人做手术。选B。