Помогите пожалуйста сделать! Put the verbs into passive forms: 1. The most important step____(take) when Mendeleyev studied the relation between die atomic weights and the properties of the elcmcnts.2. The periodic law____(accept) and widely used by chemists. 3. Properties of chemical elements and compounds (thoroughly study) in laboratories.4. Some elements _____(give) hew places in the table after the revision of their atomic weights. 5. The periodic lavs ____(widely apply) by.6. Radon (discover) during the investigation of the properties of radium and radioactive substances. 6. An important role of oxygen in combustion____(discover) by Priestley. 7. The modem concept of combustion_____(establish) by Lavoisier. 8. Oxygen____(find) in the free state in the atmosphere.9, When a substance_____(attack) by oxygen, it forms an oxide or a number of oxides. 10 Many kinds of oxides_____(meet) with in the study of chemistry 11. The lecture_____(follow) by the demonstration of experiments. 12. The yield of the reaction_____(greatly affect) by temperature. 13. Attention ___(draw) to the valence of substances. 14. Attempts _____(make) to obtain pure oxygen. 15. Much attention____(give) recently to the study of this group of oxides.

1 was taken
2 was accepted
3 were.... stutied
4 were given
5 were widely applied
6 was discovered
7 was established
8 was fond
9 was attacked
10 were met
11 was followed
12 was greatly affected
13 was drawn
14 were made
15 was given