1.It was nearly 11 p.m.-------he arrived home from the bar.A

1.It was nearly 11 p.m._______he arrived home from the bar.Athat Buntil Cwhen Dwhile
我知道此题选C,为什么不是用强调结构that,而用when
类似一题：2.Was it last year ______one of my friends managed to set a new record in the Guiness?
Awhen Bwhich Cas Dthat
为什么又要用强调结构而不用when
并由此延伸一下这一类的知识点.