Fact 1: Hydropower requires damming a river. Fact 2: Hoover Dam, the first dam on the Colorado River below Grand Canyon, was built between 1931 and 1935. Given the two facts above, which of these produces hydropower?
(I) deuterostomes. (II) Wind Turbines. (III) power stations. (IV) Suez Canal. (V) trout. (VI) Old Faithful Geyser. (VII) Hoover Dam. (VIII) stations.
(VII)