Question

What can carry hundreds of people at speeds of up to 300miles per hour, all without ever touching the ground? Hint: It's not an airplane, and it's definitely not science fiction! This amazing transportation system is called the maglev train.
You may think of trains as being very old-fashioned forms of transportation. It's true that these vehicles were more popular in the early twentieth century and that they largely fell out of favor when automobiles became common. Recently, though, traffic congestion in big cities, rising fuel prices, and concerns about the environment have made many people reconsider trains. Not old-fashioned trains, either—but new, state-of-the-art models that might bring about a transportation revolution.

Worldwide, some of the most promising plans for a high-tech train revolve around the maglev concept. What makes maglev so special? The answer is in its name, which is short for "magnetic levitation"—"levitation" means floating in the air.

"Most people think of magnets as tools that are attracted to metal and will grip tightly to any metal surface. That might sound like it would delay, rather than speed up, a moving vehicle. However, sometimes magnetic forces repel each other. If you've ever tried to stick one magnet to another magnet, you may have noticed this phenomenon," said scientist Dr. Gregory McHale. "Under the right circumstances, two magnified surfaces could repel each other and cause one to literally float in the air!"

That is the main scientific idea behind a maglev train. The train actually floats above special magnetic tracks and does not touch the ground at all! This might not seem like a benefit until you consider how traditional trains, as well as most other kinds of wheeled vehicles, work. While the wheels are rolling along rails (or a road), they experience friction, the force of two things rubbing together. "Friction makes it harder for wheels to move, and causes the vehicle to burn more energy trying to keep its speed. If the vehicle was levitating, however, it would experience no friction at all, and it could move much more quickly and easily," said Dr. McHale. The lack of rubbing also means that train and track parts will not wear out nearly as quickly.

The magnetic-levitation system is powered by electricity, considered by many to be a more environmentally friendly substitute for traditional fuels such as gasoline. It would then create less air pollution, as well as less noise pollution, since the engineless train would make little or no sound other than the rush of air.

"In Japan and China, scientists are already taking huge strides in advancing maglev technology. Many other countries, including the United States, are just getting their feet wet with the maglev high-speed train concept," said Lachelle Simmons, a transportation analyst. "The major sticking point, though, is the start-up cost. It would cost many billions of dollars to establish a maglev train system in the United States. That money is badly needed elsewhere. On top of that, there is no guarantee of a return on the investment. Nobody is sure Americans would be willing to give up their cars and start regularly riding the train."

The future of maglev train technology holds a great deal of promise but also uncertainty. Only time will tell if this new form of transportation will become a major part of American life. If it does, keep your eyes open for a lightning-fast flash of color and a rush of air—you might have just spotted a maglev!

What is a drawback of maglev technology, according to the article?
A) It isn't safe.
B) It isn't fast.
C) It isn't clean.
D) It isn't cheap.

Answer 1

Answer is D, it isn’t cheap

Answer 2

D, because it states that it would take billions of dollars to make such a train, and that money is needed elsewhere.