(The whites) have been in China for five years(就括号内提问)

问题描述:

(The whites) have been in China for five years(就括号内提问)
____ _____been in China for five years
注明原因,

对“人”提问用who,特殊疑问词做主语时谓语动词用单三形式
答案是Who has