How did you manage to get to school on time you missed the school bus? A. when B

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

A. when 　 　B. if　 C. once 　 　 D. because

试题答案

A

整个句子说得是过去的事，不表示假设，只要排除了once，if，答案就只有A了。