It ( )Mike and Mary who helped the old man several days ago. A.was B.were C.are D.had been
问题描述：
It ( )Mike and Mary who helped the old man several days ago. A.was B.were C.are D.had been
答案是A,说是指代整件事.能解释一下,再举个选B的例子么
答
这是一个强调句结构,它的构成 是:It is.+被强调部分+..that/who.+剩下部分It was.+被强调部分+..that/who.+剩下部分也就是说,在这个句子中,是IT作主语,无论什么时候,谓语动词只能用单数.不存在用WERE的情况了.又如:I...