---Did you notice someone enter the classroom just now?
---Sorry, I didn’t. I _____ my lessons at that time.
| A．am doing | B．did |
| C．do | D．was doing |
Everybody except the two young boys __________ shocked by the bad news. People looked at each other in __________.
| A．was; silence | B．were; silence | C．was; silent | D．were; silent |
After you finish the exercises, you’d better have your answers ___________.
| A．checking | B．checked | C．to check | D．check |
It was getting dark, but the little boy didn’t know______________.
| A．who can he ask for help |
| B．what was wrong with the bike |
| C．where can he go to mend the bike |
| D．if he could arrive home on time or not |
I don’t doubt ____________ she can do it well, but I doubt _________ she is willing to do it.
| A．that; if | B．that; that | C．if; if | D．if; that |
It’s nice ___________ the doctor to devote all the time he has _______ for the patients.
| A．of; to care | B．for; to care | C．for; to caring | D．of; to caring |