Question

Put the correct form of the words in brackets. 

1. Coal is_______ , but we still have to use it economically. (plenty)

2. The movement of waves and tides in the ocean can be able to generate______ . (electric)

3. Scientists are looking for clean and_______ sources of energy. (effect)

4. Non-renewable energy are not_________  friendly and can have detrimental effect on our health. (environment)

5. Natural gas is less_______than coal or crude oil. (pollute)

Answer 1

1. plentiful

2. electricity

3. effective

4. environmentally

5. polluted