get sth. through one's head是什么意思?

如题
语境是Jack couldn't get it through his head that his father wouldn't let him go to camp if his grades didn't improve.

get sth done是什么意思？ get sth done是什么句型？ come to do sth.与get to do sth.区别 get sb. to do sth 是什么意思? get sb to do sth的用法 get to do with sth 什么意思 用get sth from。。。。。。sb 句 造两句 用get out of +sth造句！急！ get to do sth 鏄?粈涔堟剰镐濆晩锛 get over可直接用get over sth?