It is required in the library regulations that any book borrowed __________ by due time, or the borrower will be fined．
| A．return | B．be returned |
| C．returns | D．is returned |
__________I know the money is safe，I shall not worry about it.
| A．Even though | B．Unless |
| C．As long as | D．While |
He made a mistake，but then he corrected the situation__________it got worse.
| A．until | B．when | C．before | D．as |
Although she hates her stepmother, __________she goes to see her for the love of her father.
| A．so far | B．as a result |
| C．now and then | D．in case |
A good storyteller must be able to hold his listeners’ curiosity__________he reaches the end.
| A．when | B．unless | C．after | D．until. |
The fire was finally brought under control,but not
__________heavy damage had been caused.
| A．before | B．after | C．since | D．as |