这几道英语语法题应该选什么?

题目

这几道英语语法题应该选什么?
老规矩,为什么选这个啦,
5． I was giving a talk to a large group of people,the same talk I ______ to half a dozen other groups before.（0 分）
A． was giving
B． am giving
C． have given
D． had given
20． It’s time we ______ the lecture because everybody has arrived.（0 分）
A． will start
B． started
C． start
D． shall start
25． I have been looking forward to ______ from my parents.（0 分）
A． be heard
B． hearing
C． hear
D． being heard

答案

D主句是过去进行时,后面说他以前就跟别人说过这样的话,就是过去的过去 用过去完成时
C it's time (that)+一般现在时,这是一个固定的句式
B look forward to +doing,to是介词.
相信我和二楼没错的,不要给其他答案误导.