--Do you know when it was that they got to know each other --It was last year___--Do you know when it was that they got to know each other --It was last year___they both taught in Scotland为什么填when,不填that?不是强调句吗?是不是因为第一句有when的原因?

问题描述:

--Do you know when it was that they got to know each other --It was last year___
--Do you know when it was that they got to know each other
--It was last year___they both taught in Scotland
为什么填when,不填that?不是强调句吗?是不是因为第一句有when的原因?