Tom was disappointed that most of the guests _________ when he _________ at the party.
| A．left; arrived | B．had left; arrived |
| C．left; had arrived | D．had left; had arrived |
Keep on trying, you will find a way out.
| A．so | B．but | C．or | D．and |
—Would you mind my using your dictionary?
—. Go ahead.
| A．Yes | B．Sure | C．Of course not | D．Not a little |
By the time Billy was 6, hein the sea.
| A．had already swum | B．was already swimming |
| C．has already swum | D．already swam |
It was only 3 hoursthe policeman caught the robber.
| A．before | B．since | C．when | D．that |
He is the very lecturer, experience impressed us greatly at the conference yesterday.
| A．who | B．whom | C．which | D．whose |