This is an illness that can result in total blindness ____left untreated. A after B if C since D unless
_____ in thought , he almost ran into the car in front of him .
Do you consider it any good _____ the truck again ?
The bad weather meant ______ the rocket launch (发射) for 48 hours .
She was afraid _____ the dog in case it became dangerous .
We're leaving at six o'clock , and hope _____ most of the journey by lunch time .