move to closing arguments 还是应该是 move to close arguments 呢？

VOA《Defense Argues Trump Not Directly Responsible for Capitol Violence》

Senators had several hours Friday to ask questions of both sides and will move to closing arguments Saturday.

老师： move to closing arguments - move to doing sth 的意思是？ 这里用了介词to,而不是不定式to, 但假如说move to do sth 又的不同之处呢？

还有，这是ask sth of sb 结构吧？

move to 表示方向，转向某话题，当然接名词了。move to do的话，和这个是两回事。