I can ______ be a teacher. I’m not a very patient person.               

You needn’t have apologized for your absence—      , it’s hardly your fault.

—How______do you attend the evening classes?—______,three times per week.

He _____ tasted the mixture and give a smile.

________ 200BC, the Silk Road, which was the route for trade between the East and the West, was in use.