It was several minutes ________ we realized what was happening—our dog was trapped in a newly-dug tunnel.
20.I ____ ten minutes to decide whether I should reject the offer.
19.The police found that the house ____ and a lot of things ____.
18.He injured his leg and ______ couldn’t play in the game.
17._____ at the gate of the theatre, he found the ticket for the play was left at home.
16.By the end of last year, another new gymnasium _____ in Beijing.