Change the active voice into passive in the following sentences: 1)acid rain and acid snow poison rivers and lakes 100 2)many countries produce acid rain. 3)people can clean the smoke from factories and power stations,but it is to expensive.

1) Rivers and lakes are poisoned by acid rain and acid snow
2) Acid rain is produced by many countries.
3) The smoke from factories and power stations can be cleaned by people ,but it is to expensive.