8.___my daughter reaches the age of eighteen,she can apply for a driving license.

• A、Unless
• B、Because
• C、Since
• D、Once

(57)___

45.Why does the car rental company ask for the credit card number?

• A、To prevent the overuse of the car.

• B、To make sure that the car won't be damaged.

• C、To make sure the user return the car and pay for using it.

• D、To ensure that the car is safely and timely returned.