Составить предложения в пассивном залоге по временам. предложение - мною был написан реферат ( present simple,continuous,perfect. тоже самое и с past и future.) и поставить каждое в вопросительную и отрицательную форму.

The referat was written by me.
The referat was writing by me.
The referat had been written by me.

The referat was not written by me.
The referat was not  writing by me.
The referat had not been written by me.