A、Synthetic fuel. B、Solar energy. C、Alcohol. D、Electricity. D短文中提到，未来几十年，人们出行的方式将与现在非常不同，每个人都将驾驶着电动汽车，故答案为D。

In the next few decades, people are going to travel very differently from the way they do today. Everyone is going to drive electrically-powered cars, so in the few years, people won’t worry about running out of gas. Some of the large automobile companies are really moving ahead with this new technology. F&C Motors, a major auto company, for example, is holding a press conference next week. After the press conference, the company will present its new electronically-operated models. Transportation in the future won’t be limited to the ground. Many people predict that traffic will quickly move to the sky.In the coming years, instead of radio reports about road conditions and highway traffic, news reports will talk about traffic jams in the sky. But the sky isn’t the limit. In the future, you will probably even be able to take a trip to the moon. Instead of listening to regular airplane announcements, you will hear someone say: the spacecraft to the moon leaves in 10 minutes. Please check your equipment. And remember no more than 10 ounces of carry-on baggage are allowed.
16. What will be used to power cars in the next few decades?
17. What will future news reports focus on when talking about transportation?
18. What will passengers be asked to do when they travel to the moon?