----Have you seen____pen﹖I left it here this morning. -----Is it____black one﹖I think I saw it somewhere.
When he was sixty years old, he _____ his hometown.
______ you understand the rule, you can do it well.
The room ____ voices of the children.
I can hardly heat the radio. Would you please ______?
They made an important decision ______ the end of the meeting.