If she could make it, she would be the first person in the world who did it.定语从句中,先行词有first等序数词修饰,要用that作引导词。但正确答案是who,请英语老师帮忙解释一下,谢谢!
刚才我查了资料,因为先行词和定语从句被状语in the world隔开了,所以必须使用who,而不能用that。这句话是山西省2018年中考选词填空的原题。