How did you manage to get to the school on timeyou missed the school bus?A. whenB. ifC. on

问题补充：

How did you manage to get to the school on timeyou missed the school bus?

A. when

B. if

C. once

D. because

答案：

(答案→)A. when

B. if

C. once

D. because

解析：考查状语从句。句意：既然错过了校车，你是怎样做到准时到校的？when除了有“当”的意思之外，还有“既然”的意思，相当于now that。故选A。