Modern civilization is heavily dependent (26)   energy. Without reliable power sources, we couldn’t operate machines, use transportation, communicate via the Internet, or do many other things. Although everyone recognizes the importance of energy, deciding what kind of energy the world should use in the future is not a (27) task. The two leading candidates for this role are green energy and nuclear energy.

Currently, (28) of the energy we use is derived from fossil fuels. Although this energy source has provided people with a lot of benefits, there are several problems with it. For starters, it is a finite resource which is (29) running out. Some analysis have even estimated that the Earth could run out of coal and oil within the next 50 years. Burning fossil fuels also creates a large amount of (30) , which is harmful to the environment. Although fossil fuels still provide the majority of our power, governments are seeking better energy sources to use.

Read the following passage and choose the most suitable word from the ones given in the box to fill in each gap. Write the answers on your answer sheet.