Change from the active into the passive.
1.Tchaikovsky used many folk-tunes in his compositions.2. The agronomist has introduced new methods of work in agriculture. 3. The lecturer showed his students a recently devised apparatus. 4. We all must look after the children. 5. The population of France gave the Russian delegation a hearty welcome. 6. The gardener asked me to help him in the garden.7. The students of this group are translating the English text. 8. They finished their work earlier than usual. 9. We have sent him a telegram. 10. The students were discussing the problem at 6 o’clock yesterday. 11. You must buy a new English dictionary.

1. Many folk-tunes were used in Tchaikovsky's compositions.2. New methods of work in agriculture have been introduced by the agronomist. 3. A recently devised apparatus was showed lecturer's students. 4. Children must be looked after all of us. 5. The Russian delegation was given a hearty welcome by the population of France. 6. I was asked to help in the garden by the gardener .7. The English text is being translating by the students. 8. Their work was finished earlier than usual. 9. A telegram has been sent.10. The problem was being discussing by the students at 6 o’clock yesterday.11. A new English dictionary must be bought.