A good friend of mine from when I was born at my home right before I left for Beijing．A.

问题补充：

A good friend of mine from when I was born at my home right before I left for Beijing．

A. showing up

B. showed up

C. to show up

D. shows up

答案：

A. showing up

(答案→)B. showed up

C. to show up

D. shows up

解析：考查谓语动词：from when I was born是定语修饰A good friend of mine，show up是谓语动词，用过去分词，句意：我的一个发小就在我去北京前来到我家。选B。