The policeman was ________ abusing his power when performing his duty, but it hasn’t been ______ yet. 

  —How do people do bird-watching? —Sometimes they______the birds quietly,  sometimes they use telescopes. 

Experienced as she is, the teacher is still thinking of new ideas about how the new textbooks should be ______ .

Her leg has been ______ for quite a while, which ,in the meawhile, makes_____for her parents.

I ___ get on the bus when I heard someone calling me from behind.’