Ответ:

1) Teacher will ask you at Maths lesson tomorrow.

You will be asked at Maths lesson tomorrow.

2) They showed this film last year.

This film was shown last year.

3) "Our team will win the prize",said the boy.

"The prize will be won by our team", said the boy.

4) Most people in the country speak English.

English is spoken in the country by most people .

5) The girl cleaned the room yesterday.

The room was cleaned yesterday by the girl

6) A group of artists organized this original exhibition.

This original exhibition was organized by a group of artists.

6)Their team lost the game yesterday.

The game was lost yesterday by their team.