---did jack come back early last night?

题目

---did jack come back early last night?
---yes.It's was not yet eight ___he arrived home.
1.until
2.when
详解为什么

答案

选when
杰克昨天回来的早吗?
是的,他到家的时候还不到8点呢.
not .until是直到.才的意思,放在这里不符合句子意思.