—Where is our English teacher? —She is in the classroom, _____ the exercises _________ the students have done at home.
How long is it ______ we last spent the holiday in the country together?
The head of the company promised to deal with matters of this sort ____ he returned to his office.
He will have learnt English for eight years by the time he _____ from the university next year.
The airline said the two flights to Shanghai were stopped ______ passengers.
Since then, finding ways ______ more peanuts has been his life goal.