Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to eachRead the following passage and mark the letter A , B , C , or D on your answer sheet to indicate the correct answer to each of the questions . two and four meters in diameter . Australia has always been famous for its beaches and exhilarating waves . But the ocean offers more than just a surfer's paradise : its tides are also a source of renewable energy . Among those harnessing this tidal potential is the Sydney - based company Mako Energy , which makes underwater turbines ranging between two and four meters in One turbine operating in constantly flowing water can have an energy output great enough to power up to 20 homes . Their design enables them to generate electricity even in slow - flowing water , meaning they could be used in rivers . " We're developing them at a scale where they can be deployed easily in remote communities , coastal businesses , island communities and resorts , " said Douglas Hunt , managing director of Mako Energy . Although tidal energy is still in its infancy , it could help to reduce Australia's dependence on fossil fuels. The island nation is only beginning to explore tidal power through a small number of projects . But this form of energy has already showcased one major advantage : predictability . While the sun may not always shine and the wind may not always blow , the sea's tidal currents moves in very predictable patterns . This means that tidal energy is easily the most reliable source of renewable energy . However , installing tidal energy systems can be very costly . A Mako turbine costs between 20,000and20,000and 70,000 , depending on the power output and the location . Large tidal energy systems can be expensive to install . So far , Mako's customers have predominantly been large industrial and government sites , but it wants to make its turbines accessible to energy customers big and small . " Tidal turbines have been around for quite some time , but the challenge has been to build them in a more economical way , " said Hunt Reducing costs means turbines would become available to everyone , from companies to households with access to flowing water . There are also other challenges to overcome . One 2017 EU report points to a lack of research into the possible effects of tidal installations on marine life , and another points out high construction costs as a barrier to the deployment of tidal power worldwide . A. their large diameters B. their special design C. their energy output Question 44 : Which best serves as the title for the passage ? A. Worldwide Tidal Energy Systems : What Are The Challenges ? B. Energy From Waves : Attractive But Not Without Difficulties C. Tidal Energy : Both Expensive And Damaging To Marine Life D. How Tidal Energy Systems Are Becoming More Accessible Question 45 : The phrase " they " in paragraph 2 is closest in meaning to.............. A. turbines B. homes C. rivers D. communities Question 46 : According to paragraph 2 , Mako Energy's turbines can work in rivers thanks to............ A. their large diameters C. their energy output Question B. their special design D. their great scale Question 47 : Which is likely the reason why Mako's customers have mainly been large industrial and government sites ? A. Because their systems do not generate enough energy for households. B. Because tidal turbines are still a relatively new invention . C. Because building economical tidal energy systems is simply impossible . D. Because it can be expensive to install tidal energy systems . Question 48 : The word " showcased " in paragraph 3 is closest in meaning to.......... A. announced B. publicized C. exhibited D. disclosed Question 49 : The phrase " easily " in paragraph 4 can be best replaced by............ A. effortlessly B. smoothly C. quickly D. probably Question 50 : Which of the following is TRUE , according to the passage ? A. Mako's turbines can power more than 20 homes when operating . B. It will not be very easy to construct tidal energy systems in a more economical manner . C. Tidal energy has long been researched and developed in Australia . |