You can never imagine the great difficulty I had ______ her QQ number.

What are you doing there?—I’m going hiking _______ the mountains. I like going there _______ vacation. [ ]

Did you see a man in black pass by just now?——No，sir．I___________a newspaper．

_________ my two sisters. And __________ my brother.

Miss Gao teaches _______ English. We all like her lessons.