Active or passive voice 5) we have lost our keys. - 6) you might see dolphins here. - 7) the report must be completed by next friday. - 8) they were singing a song in the lesson yesterday. - 9) a letter was written to her some days ago. - 10) the black bike is being repaired at the moment. -

5) We have lost our keys. – Active
Our keys have been lost.
6) You might see dolphins here. – Active
Dolphins might been seen here
7) The report must be completed by next Friday. – Passive
You must complete the report by next Friday.
8) They were singing a song in the lesson yesterday. – Active
A song was being sung by them in the lesson yesterday.
9) A letter was written to her some days ago. – Passive
He wrote her a letter some days ago.
10) The black bike is being repaired at the moment. – Passive
They are repairing the black bike at the moment.