News programs, television specials, books, and newspaper articles often remind us that the world is using great amounts of energy. As an industrial nation, we use energy to heat our homes, run our machines, keep our cars, trucks, ships, trains, and planes moving, and help us enjoy life. If we’re not careful, though, our descendants may have a hard time doing the same. We are reminded time and again that we should conserve energy or look for alternative sources of energy. Will our children ask, “Why didn’t you?” or will they say, “Way to go!”

Which is the main idea of this paragraph?

AEnergy is important for transportation and industry.

BEnergy is being used too much.

CModern technology requires vast amounts of energy.

DWe need to find ways to conserve or create new forms of energy.