It is not where you come from or what you are, but the ability to do the job _____ matters.
Shortly after we ______, a waiter came over to us with a smile.
The reason _____ he gave for not coming to your birthday party is ______ his mother was ill.
Who do you think the teacher will ______ the question?
The man will have to wait all day ______ the doctor works faster.
With a lot of difficult problems ______, the newly-elected president is having a hard time.