—What made you so tired?—__________ driving all day.
I’m thinking about going to Germany this summer and I need your advice. You’re the best person I know to answer my questions,____you’re German.
I was advised to arrange for insurance(保险) _______ I needed medical treatment.
—We’re supposed to be there at 6:00?—_______ I know.
I thought things would get better, but _____it is they are getting worse.
Although he knew little about the large amount of work done in the field , he succeeded ____other more well-informed experimenters failed.