what作引导词引导宾语从句

做主语？

在这儿，what引导的从句具有插入语性质， 用于表示对某种概念的评价、推断、补充说明的含义， 这种从句翻译时比较灵活，不宜译为“……的东西”。
再如:
The soldiers drilling on the playground were carrying what looked like real guns. 操场上操练的士兵好象扛着真枪。
In 1492, Columbus reached what is now called America. 1492年,哥伦布到达了现在所称的美洲大陆。
In finding something less dangerous to throw, the Egyptians invented what was probably the first ball. 在寻找不那么危险的东西投掷的时候, 埃及人发明了一种球,那可能是最早的球。
He put forth what seemed to be good reasons. 他申诉了理由，似乎颇有道理。
In the darkness, I felt my way into what I thought was my room. 在黑暗中，我摸索着进了一个房间，我以为那就是我的房间。
The young girl was too frightened to speak. She just stood there holding on to the door for what seemed like hours 小女孩吓得不敢说话，只是靠着门站着，好像站了几个小时。

what 作从句的主语。