You are presented with the quiz "Hydropower requires what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "hydropower requires damming a river" and "many dams along rivers and creeks help prevent floods". So, what's the best answer to the question?
Options:
(1). a hydraulic system;
(2). increases a body's strength;
(3). helping to prevent floods;
(4). Electric generators;
(5). flow of electrons;
(6). energy of moving objects;
(7). power stations;
(8). fissures of hot, acidic water;
Answer:
(3).