________hard before, Tom is afraid of failing in the exam.
| A．Having been worked | B．Not to have worked |
| C．Having never worked | D．Never have worked |
. _______ I know the money is safe, I shall not worry about it.
| A．Even though | B．Unless |
| C．As long as | D．while |
A good storyteller must be able to hold his listeners’ curiosity ________ he reaches the end of the story.
| A．when | B．unless |
| C．after | D．until |
Don’t be afraid of asking for help _______ it is needed.
| A．unless | B．since |
| C．although | D．when |
I raised the alarm _______ I saw the smoke.
| A．while | B．the minute |
| C．suddenly | D．since |
The doorkeeper gave the alarm _______ he saw the smoke.
| A．while | B．the instant |
| C．suddenly | D．before |