_a certain doubt among the students as to the necessity of the work.为什么用there excisted 而不用it
问题描述：
_a certain doubt among the students as to the necessity of the work.为什么用there excisted 而不用it
答
本句型是倒装句：There + be动词或不及物动词+主语(名词)
There is a book on the desk.
There comes a man of fifty.
There followed a group of children.