UNIT 6 THE GREEN ENVIRONMENT - EXERCISE 1

Circle the correct option to indicate the correct option that best fits each of the following numbered blanks from 18 to 22
BIOMASS FUEL AND TIDAL ENERGY
Biomass is material that comes from trees, recycled paper, animal waste, food waste and some crops, such as corn, soy and sugar cane. In other words, most kinds of produce waste ___(1)___.
The biomass is dried and then burnt as biomass fuel to create heat or generate electricity. Biomass fuel is easy to store for use when we need it. However, ___(2)___, a greenhouse gas, so it is not completely environmentally friendly. The good news is that biomass fuel is carbon neutral because it only releases the same amount of carbon into the atmosphere as the plants, the source of biomass fuel, absorb in their life cycle. We can also make biofuel from biomass and ___(3)___.
Biofuel produces fewer emissions than regular petrol. To illustrate, E5 petrol contains 95% of normal petrol and 5% of ethanol, a kind of biofuel; E5 really helps ___(4)___. However, growing crops for biomass fuel uses a lot of land and is only renewable if we replant trees.
Tidal energy involves converting the energy of the waves in large bodies of water such as seas, oceans and lakes into electricity. ___(5)___ by installing large turbines on the seabed or below the sea surface. Similar to hydroelectricity, continuous ocean currents can turn huge turbines and generate electricity. Tidal power doesn't produce any greenhouse gases, and it is a highly efficient form of energy because it can produce electricity continuously at all times of the year. However, tidal power hasn't been popular yet because it requires huge investments, effective management and regular maintenance.
(Adapted from Bright)