how to solve the problem, the little boy turned to his father for help.
| A．Not knowing | B．Having not known |
| C．Not having been known | D．Not known |
—Tom, you didn’t come to the party last night?
—I __________, but I suddenly remembered I had homework to do.
| A．had to | B．didn’t |
| C．was going to | D．wouldn’t |
When I called you this morning, nobody answered the phone. Where __________?
| A．did you go | B．have you gone |
| C．were you | D．had you been |
—Did Alan enjoy seeing his old friends yesterday?
—Yes, he did. He __________ his old friends for a long time.
| A．didn’t see | B．wouldn’t see |
| C．hasn’t seen | D．hadn’t seen |
The play had already been on for quite some time when we __________ at the New Theatre.
| A．have arrived | B．arrived |
| C．had arrived | D．arrive |
Professor James will give us a lecture on the Western culture, but when and where __________ yet.
| A．hasn’t been decided | B．haven’t decided |
| C．isn’t being decided | D．aren’t decided |