III)-Complete the sentences, using the correct form of the words in brackets. 1. The soil becomes _______________ because of the use of so many pesticides and fertilizers. (contaminate) 2. _______________ waste spills can contaminate groundwater. (industry) 3. In many developing countries, water pollution is usually a leading cause of ________________. (die) 4. ____________ elements have been found in both ground and underground water sources. (pollute) 5. Fish and many other animals are killed by ______________ in their habitat. (pollute) 6. Astronomers are concerned about light pollution because they have __________ in viewing activities in the sky and outer space. (difficult)