They have no idea at all ____________.
Several months later, he found his deskmate very difficult _______.
In order to make up for the lost time, they are working ______.
She used ______ on the right in China, so she was not used _______ on the left in England at first.
____ finishing his homework, he went to play basketball.
He tried to invite some famous pop stars to sing in the concert ______, but failed.