Can you tell me ______ to join the army?
| A．how does a person have to be old | B．how old does a person have to be |
| C．how old a person has to be | D．how a person has to be |
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 leftyou 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 |
Hearing his words ,I couldn’t decide or remain .
| A．whether to go abroad | B．if I go abroad |
| C．if to go abroad | D．to go abroad |
Questions and exercises are given by the computer, which decides ______ to move the students ahead, review an easier level, ____ give more work on the same level.
| A．either, or | B．both, and . | C．whether, or | D．not only, but also |