지문이 확실하게 해석이 안되서 아마 문제 푸는데도 틀린 것 같아요. 정답이 B인데 B보기에 'falls away quickly' 가 어느 부분이 페러프레이징이 되었는지도 감이 잘 안잡혀요. 부탁드립니다.
5. According to paragraph 4, which of the following was discovered as a result of scientific and technical investigations of waterpower conducted between 1650 and 1800?
A. Some types of small waterwheel can produce as much horsepower as the very largest wheels.
B. Waterwheels operate more efficiently when water falls away from their blades slowly than when water falls away quickly.
C. Waterwheel efficiency can be improved by increasing the amount of kinetic energy water contains as it passes over a waterwheel’s blades.
D. Unlike other types of waterwheels, the overshot wheel is capable of producing more than 60 horsepower units of energy.