It will take us about four hours ——（get）there by bus.It‘s co

It will take us about four hours—to—get there by bus。It‘s cold in the room and I have to wear a thick jacket _to_keep myself warm。Kitty is one of the _first__(one)students to join the club。The students are very _excited- about their coming school trip。第一句是句型：It takes/will take sb some time to do sth。所以要填动词的不定式。第二句是动词不定式用作目的状语。意思是“为了给我自己保暖”。how long是指动作“持续”了多久。how soon是指动作“还要多久”发生。 再问： 能解释一下不定式吗？谢谢，我弄明白一定及时采纳！