______ you understand the rule, you can do it well.
| A．For | B．As | C．Once | D．While |
The hall of the school canone thousand people.
| A．sit | B．seat | C．be sat | D．be seated |
If you are able to talk to a friend over the telephone, you feel that you are close ____ the actual distance is not shortened.
| A．so long as | B．if | C．even if | D．as |
—I felt it very difficult to carry on the work all by myself.
—I could have helped you, but you _____me to.
| A．hadn’t asked | B．didn’t ask | C．haven’t asked | D．don’t ask |
Mr. Smith has bought a new house in the country, around ____ some green trees.
| A．which is | B．it is | C．which are | D．them are |
All the task ahead of time, they decided to go on holiday for a week.
| A．had been finished | B．were finished |
| C．having been finished | D．been finished |