On the National Day, up _____ into the air. Then the crowed cheered.
She locked her room _____ a thief would break into it.
She said she would spend her holiday ___ Beijing.
Whenever I go to Beijing, ____ is quite frequent, I will go to visit the Great Wall.
They told us that these small apples are often sweeter than big ____.
The girl ____ a beautiful skirt has told me the news. Which is not right?