. He must be curious about everything in the lab, for this/that/it is the first time that he has been there, ________?
Then ________ we had been looking forward to.
—I’m sorry I broke your teapot.—___________
I was advised to arrange for insurance(保险) __________ I needed medical treatment.
—Are you going to the football game this weekend? —Probably not. The tickets are __________ for me.
—Where is our English teacher? —She is in the classroom, ________ the exercises _________ the students have done at home.