—Did you visit the museum last week ?
—No, we ___, but we spent too much time shopping.
| A．could have | B．could |
| C．must have | D．must |
Only thirty per cent of ______ parents say that they know what their children like to do after _____ school.
| A．/, the | B．a ,the | C．the, / | D．a, a |
. I want to be very careful to talk only about ____ we've formally tested.
| A．which | B．that | C．what | D．whether |
If we had taken the other road, we ________ earlier.
| A．would arrive | B．might arrive | C．had arrived | D．might have arrived |
The driver _____, according to the newspaper, to have been killed in the traffic accident.
| A．said | B．was saying | C．was said | D．had been said |
．— Have you ever visited the Opera House?
—Yes．When I was in Sydney, I ______ it twice．
| A．have visited | B．visited | C．had visited | D．would visit |