is that your parents 还是are those your parents?

题目

is that your parents 还是are those your parents?
答是：Yes ,they are
辅导书里的答案是is that your parents
我觉得很奇怪,为什么
那我们怎么分别用is that还是用are those呢
考试遇到填什么

答案

这里的that与平时讲的意思有所不同.当所指的人不确定时,（如：电话里,或只是听到某人的声音）,这时代词都要用that,而不用those,更不用they,而无论其是否单数.答句用复数,那是因为回答者心中清楚那个“that”实实在在...