Turn these following sentences into the passive voice.

I finished my work at about five o'clock.

-> ________________________________________________________________.

We have learnt English for five years.

-> ________________________________________________________________.

Do people speak English all over the world?

-> ________________________________________________________________.

He opened the boxes and took out a cigarette.

-> ________________________________________________________________.

They built this house in 1995.

-> ________________________________________________________________.

You must answer all the questions on the paper.

-> ________________________________________________________________.

Someone is singing an English song.

-> ________________________________________________________________.

Somebody planted this tree last month.

-> ________________________________________________________________.