Rewrite the sentences using passive structures they received a patent for the invention of this medicine fifteen years ago. who discovered the penicillin? they are introducing new software now. they are developing a new model of a digital camera now. who invented the sewing machine? when will they use new software?

A patent for the invention of this medicine was received  fifteen years ago.
Who was  the penicillin discovered by?
New software is being introduced  now.
A new model of a digital camera is being developed  now.
Who was the sewing machine invented by?
When will new software be used?