The chairman ________ hold office for five years according to the constitution.

When I was your age, I dared not go out alone at night, ________ you?

 Personally, the job as a teacher _____ be challenging, for I sometimes _____ deal with some smarter but less diligent students. 

 ---Who’s the man over there? Is it Mr. Black?--- It _________ be him. He’s much taller.

 –I can’t stop smoking, doctor. --For your health, I’m afraid you________.