I hate ______ when the weather becomes freezing cold because there is no heater inside.
The worker can make chairs ____ wood, and also can make paper ____ wood.
The teacher is writing ____ a piece of chalk on the blackboard while the students are writing ____ink in exercise books.
—You know. Bob is a little slow ____ understanding, so… — So I have to be patient ______ him.
We were just about ready to leave _____ it started to snow.
_____ the government agrees to give extra money , the theatre will have to close.