Question

---When did you get to know each other ?
----It was in 2008___      we spent summer vocation together.

A．that

B．when

C．before

D．since

Answer 1

B

考查定语从句。先行词为2008，从句中缺少时间状语所以用关系副词when，句意：你们什么时候开始认识的？就是在我们一起度过暑假的2008年。所以选B。