An unhappy childhood may have some negative effects on a person's character; however, they are not always __________.
He is running ____ the wind towards the east of the station ____ Tom is running ____ the right.
I don't think you can work out the maths problem ____ the teacher's help.
My uncle lives ____ 105 Huanghe Street. His room is ____ the fifth floor.
My father was disappointed ____ the news.
His teacher was angry ____ him ____ his being late.