问题补充：
All but one ＿＿ take part in the conference ＿＿ tomorrow.
A. is going to； that is to take place
B. are going to； that is about to take place
C. are going to； that is to be taken place
D. are going to； which is to be held
答案：
A. is going to； that is to take place
B. are going to； that is about to take place
C. are going to； that is to be taken place
(答案→)D. are going to； which is to be held
解析：all but one 主语是all，且all在此指人，故谓语动词用复数；take place 属不及物动词短语，无被动语态；be about to后面不能跟具体的时间状语。
