While we were running on the playground,Jack suddenly stopped ___________ and lay on the ground,so we all stopped ___________ what was wrong with him.
---Which of the two T-shirts will you take? ---I’ll take ___, one for my father, the other for myself.
She’s read the book, _____?
The Whites _____ many places of interest last year.
---Where are the Greens, may I ask? ---Well, they _____ to England. They will come back in a week.
---_____ you ever _____ to Nanjing? ---Yes, I _____ there last year.