主语从句的练习题,有没有英语大神会的,
问题描述：
主语从句的练习题,有没有英语大神会的,
_____ was once regarded as impossible has now become a reality.A.That B.Which C.Who D.What
答
选D.what
_____ was once regarded as impossible这是主语从句,这个从句中缺少主语.
选项中只有what和who能单独做主语.who是指人.而这里是指事物,所以用what.