Jack his pet dog every day. The dog must feel sad when he’s alone all day long.
---It was ___________ who helped us out of danger.---What brave and helpful children! We should learn from them.
My mother was doing the cleaning in the sitting room ________ the telephone rang.
Every day, too much water _______ in our school. We should save it.
— Must we go to see a doctor at once when we have the flu?—No,_____.A. we mustn’tB. we shouldn’tC. we don’t have to
— ____ you _______your book to the library? — Yes. I returned it yesterday. A. Did, return B. Have, returned C. Will, return