You\'ve probably heard of people using solar panels to create electricity for their homes. You may even own a solar powered calculator. But did you know that in 2013, a solar powered airplane flew across the entire U.S. without using any fuel or creating any pollution? Although this is only the beginning as far as solar airplanes are concerned, the world may soon be a cleaner place.
This story behind Solar Impulse begins with its creators, Swiss pilots Bertrand Piccard and Andre Borschberg. Both men are experienced aviators, but they come from different backgrounds. Borschberg is a former fighter pilot and an engineer. Piccard is a physician and the first person to fly a hot air balloon around the world. Together, the two used their varied knowledge and experience to create Solar Impulse. It was a project that took ten years and cost $115 million to complete. The plane, which weighs only about as much as a small car, collects the sun\'s energy via about 12,000 solar cells on its wings. The energy is stored in special batteries. The batteries power the dour electric motors that turn the plane\'s propellers.
Solar Impulse flies fairly slowly if you compare it to a standard passenger plane. It reached speeds of about 50 miles per hour on its own but can fly twice as fast with tailwinds boosting its speed. In comparison, a commercial Boeing travels between 500 to 600 miles per hours. This isn\'t a great concern to Solar Impulse\'s creators, who aren\'t in a great hurry. At this point, they are just happy that they\'ve made as much progress as they have.
Solar Impulse\'s journey across the U.S. was not its first record setting flight. In 2010, the pilots completed their first night flight over Switzerland (using the energy stored in batteries from the daylight\'s sunshine). The next step was an international flight from Switzerland to Belgium to France. Solar Impulse even flew to Africa in 2012, setting a record for the longest flight by a solar aircraft--nearly 700 miles.
For Piccard and Borschberg, flying across America, the birthplace of aviation, was a logical next step. The flight departed from San Francisco, on May 3, 2013. After stops in five cities around the country, the pilots completed the last leg of their trip on July 6, as they touched down in New York. The flight was 3,511 miles and took nearly 106 hours.
The trip was not without problems, such as tornadoes, thunderstorms, and extreme heat, but the pilots used these encounters as learning experiences. Even the long hours spent in the plane were a chance to learn. The cockpit is small, and staying comfortable, eating, sleeping, and staying alert are all challenges. Piccard and Borschberg want to get it right because their next planned trip is quite a bit more ambitious. In 2015, the duo plans to fly around the world in a solar powered plane. They are building a second plane, Solar Impulse 2, and hope to complete the trip in 20 days. Aside from the thrill of setting world records and trying things that have never been done begore, the Swiss team hopes to bring the world\'s attention to the potential of clean, green technology. With a little creativity and a lot of know-how, every idea has the chance to become a reality.
问题:
1. If Solar Impulse is powered by the sun, how does it fly at night?
2. Why are Piccard and Borschberg a good team?
3. How did the pilots regard the problems they had during their journey across the U.S.? (选择题)
a. as learning opportunities
b. as great sources of frustration
c. as a reason to abort the trip
4. What do Piccard and Borschberg have planned for their next major trip?
5. Name two ways in which Solar Impulse is similar to and different from a conventional airplane.
6. In the next to last sentence of the selection, what do you think the author means by \"clean, green technology\"?
7. Solar Impulse can travel faster than its typical 50 miles per hour speed with the help of ________. (选择题)
a. gasoline
b. wind
c. extra propellers
8. Do you think that solar-powered airplanes will become more popular in the future?