问题补充：
The doctor telephoned to say that he couldn’t the meeting because he had to a patient.
A. came to; attend to
B. attend; attend
C. join; treat
D. attend on; look after
答案：
A. came to; attend to
(答案→)B. attend; attend
C. join; treat
D. attend on; look after
解析：参加会议常用attend/ be present at the meeting，照看病人用attend（on）a patient/ look after a patient。
