VII. Fill in each blank with a suitable word from the box to complete the passage heat also replace produced popular nations 1. Biogas is a form of biofuel produced from animal manure (phân), human waste and plant material. It is a renewable 2. energy source which can be used to (26) ____________________ fossil fuels such as oil, coal and natural gas. 3. Nowadays, it can be used to power motor vehicles, generate electricity and (27) ________________________ homes. 4. Using biogas can (28) ______________________ help us reduce our carbon footprint. In addition, biogas has positive 5. health benefits for residents of rural areas. Traditionally, biogas is a (29) _____________________ source of fuel for 6. households in developing (30) __________________. China is the largest producer of biogas in the world. In Europe, 7. biogas has been (31) __________________ as an alternative fuel since the 1920s. The most significant biogas 8. producer is Germany