—— ______ if I smoked? ——I'm sorry, but it's not allowed.
I could just see a car in the distance, but I couldn’t _____ what color it was.
What did you ____ me ____? I’m a teacher, not a doctor.
The new discovery is of ________.
Once _____ , the machine will keep running.
____ in thought, he almost ran into the car in front him.