So many directors the board meeting had to be put off.A. were absentB. been absentC. had

问题补充：

So many directors , the board meeting had to be put off.

A. were absent

B. been absent

C. had been absent

D. being absent

答案：

A. were absent

B. been absent

C. had been absent

(答案→)D. being absent

解析：提示：“名词＋doing……”构成独立主格结构，表示原因。