Only then _________ that I can erase the wrong words I have written, but I can’t erase the things I have done.
| A．did I realize | B．have I realized |
| C．I realized | D．I did realize |
―________ you _________ the chief editor at the airport?
―No. He _______ away before my arrival.
| A．Have; met; has driven | B．Had; met; was driven |
| C．Did; meet; had been driven | D．Have; met; was driven |
―Did you meet Professor Johnson?
―Yes, but when I arrived, he ________, so we only had time for a few words.
| A．had just left | B．has just left |
| C．was just leaving | D．just left |
―Have you finished your composition already?
―Yes. I _________ it in twenty minutes.
| A．have finished | B．finished | C．will finish | D．had finished |
He traveled to many mountain villages and saw many poor children out of school. This experience _______ his life.
| A．would change | B．had changed |
| C．was to change | D．was changing |
You _______ things about. Look, what a mess in your room.
| A．always throw | B．have always thrown |
| C．are always throwing | D．have always been throwing |