I think (it) must be our monitor.为什么填it?

I think (it) must be our monitor.为什么填it? I think it must be的意思 I think it must __somewhere else.填什么 I think it must be very nice中文 i think it must be in your room,____? Darling .I am very happy to be your wife .I think it must be .---Well,I found this.I think it must be yours.---Where_____ When I saw a story book,I think it must be John 's but my friends and i think it must be teenagers having fun为什 I will think it must be John's.这句话对嘛?. I think it must be very nice on m------ 首字母填空 高中情态动词-That must be a terrible mistake .-No.I don't think it