—All the lights have gone out in the office building.
—Yes, they have __________ electricity.
| A．cut off |
| B．cut up |
| C．cut in |
| D．cut down |
John waited at the bus-stop for nearly half an hour _____ the bus finally arrived .
| A．when | B．as | C．before | D．while |
Not that I’m unwilling to lend you a hand , ____I’m too busy for the moment .
| A．because | B．but that | C．but | D．however |
Jack had traveled six miles across the Channel _____his engine failed and was forced to land on the sea .
| A．when | B．until | C．after | D．since |
—When did he leave the classroom?
—He left _____you turned back to write on the blackboard.
| A．the minute | B．the time | C．until | D．before |
____he thought he was helping us with the work, he was actually in the way.
| A．Although | B．Unless | C．Because | D．When |