依次填入下列句子横线处的成语最恰当的一项是（ ）①胡歌坐下来看剧本 时 ，等到他表演，他仔细揣摩人物心理、台词，完美演绎了“梅长苏”这个角色。②卢嘉川不说话了，他好像陷入沉思的状态中，正襟危坐， ，苦苦地思索着什么，回忆着过去发生的一切。③那时候，知识的总量还没那么大，如果你 几十年，就可把所学的那个专业的门类全部拿下。

guishedguests and friends, welcome to our school, theceremony of the 50th Anniversary this morning are our alumni from home and abroad.

I don’t know how to learn English well. Will you please give me on it

She will be a doctor—— two months.

People will have ______ free time and ______ housework to do in the future because robots can help a lot.