Word Selection

1 The driver of a fuel cell powered car might say, "Fill ‘er up with ______. gasoline hydrogen oxygen kerosene 2 The new car is a ______ of possible cars for the future. prototype generator complication complex 3 A fuel cell is a power _______ . prototype generator complication complex 4 According to the article, hydrogen is ________ . cheap dirty convenient flammable 5 The fuel cell _______ separates the hydrogen protons and electrons. membrane emission flammable ramp