Ex. 6. Insert the needed verbs: 1. Chemistry is the science which ... with materials and their properties. 2. We think that the exhibition of our achievements will ... at the end of September. 3. This scientist ... a great contribution both in chemistry and physics. 4. All his life he worked in the field of chemistry, and we can say that he ... his life to science. 5. All the changes which ... this reaction play a very important part. 6. Later Lavoisier ... the concept of the chemical elements. 7. This article … with the development of our industry.