If she spent five years in Paris, how come her French is so bad?

既然她在巴黎待了五年，她的法语怎么还会这样糟糕？

《牛津词典》

"They don't say a single word to each other."—"How come?"

“他们相互不说一句话。”—“怎么会这样？”

《柯林斯英汉双解大词典》

"How come we never know what's going on?" he groused.

“我们怎么会不知道发生了什么事？”他抱怨道。

《柯林斯英汉双解大词典》