题目内容：

So many directors___the board meeting had to be put off.
A)were absent B)been absent C)had been absent D)being absent

优质解答

选 D这里是用非谓语形式,因为这里不是复合句,即不是从句,所以同一个简单句里边不能容纳两个谓语形式存在,只能处理成非谓语形式.排除了 A和 C这两个是谓语形式.非谓语形式分为三种：现在分词（动名词）doing sth,表主...