8. He was so deep in thought, thinking of the problem ______ he knocked into the tree without noticing it.
I don't suppose that homework means everything in senior high school, __________?
Today we feel proud __________ our school.
Lisa __________ eat lots of desserts after supper, so she was very fat then.
There __________ some old black leather baskets in the corner of the dust room.
The old man used __________ in front of his house and he has got used to __________ like that.