Millie, who are you waiting ______ the bus stop? [ ]

Must I clean up the classroom right now, Miss Green?– No, you ______.

Our classroom is very dirty ,let’s _____it_______.

By the end of the last month, I _____________ all the CDs of Justin Bieber.

The speech by the mayor of Shanghai before the final voting for EXPO 2010 is strongly impressed ___ my memory.