II. Supply the correct form of the word in parentheses to complete each sentence. (1m)

1. Thousand of people were left homeless after the _____________ eruption. (volcano)

2. Do you know that the telephone, the television and penicillin are Scottish __ __

(invent)

3. You mustn’t drink the water in rivers because it is ______________ (clean)

4. Industrial waste spills can ______________ groundwater. (contamination)