题目内容
（请给出正确答案）
Fly ash can partly take the place of ______.
A. paving material
B. cement
C. concrete
D. the coal by-product
如果结果不匹配，请 联系老师 获取答案
更多“Fly ash can partly take the pl…”相关的问题
What can be extracted from fine-powder fly ash？
A. Aluminum, silicon, and magnetic.
B. Additive.
C. Paving material.
D. Cement.
The Solo Trek had a 120 horsepower engine with twin fans. Only one person flies. As you fly above the roofs, you lean a little forward. You can see everything under you. You are flying like Superman.
Michael Moshier looked at the jet belt and the rocket belt that was developed 20, 30 years ago. Nothing ever came from them. People still can't fly.
Inventors have tried to make it easy for people to fly. Paul Moiler has been working on his flying car for 30 years. He now says it is ready for tests. It would take off and land vertically, go 600 miles an hour, and deliver 20 miles to the gallon. A computer would do the actual flying. He says it could be sold next year for about a million dollars.
NASA is working with Moshier to help develop his flying machine. The first users are likely to be military.
It's been 50-years since Robert Fulton invented his airphibian, a flying car. It flew, and is now in the Smithsonian Museum.
Getting dreams to fly is never easy.
The Solo Flyer is able to lift off the ground by using ______.
A．a solar powered engine
B．engine-powered twin fans
C．large flapping wings
D．rotating blades
The kids who grew up on "Star Trek" can't find (1)_____ way around Earth.
Americans can (2)_____ direct to England, but only half can find (3)_____ on a map of Europe. They can fly almost (4)_____ in the United States for a few hundred dollars, but they put New York State in 37 places on both coasts. When they look for the United States (5)_____, they (6)_____ it in China, Australia, Brazil, Russia, India and Botswana.
For people who are supposed to be leaders of the (7)_____ world, Americans are (8)_____ dumb, according to a survey conducted for the National Geographic Society.
In many school (9)_____, geography has been mixed with history (10)_____ melted down into social studies. Social studies has been processed into" teacher resource packages "and (11)_____ of good writing, excitement, color and any ideas that aren't simplistic; too (12)_____ and too deadening to hold students' attention.
In the last few years, evidence of America s educational (13)_____ has prompted hundreds of studies, generated baskets (14)_____ legislation and moved parents into advocacy groups. But there's (15)_____ to show that the trend has been (16)_____.
NO matter (17)_____ you try, you can't make it seem (18)_____ that many Americans say pandas come from Panama, the Summer Olympic Games were held in Vietnam or (19)_____ Iraq, and Columbus was trying to get to Europe when he bumped into (20)_____.
A．it's
B．the
C．their
D．a
"If your computer is down, just write me out a ticket."
"I can't write you out a ticket. The computer is the only one allowed to do so."
I looked down on the computer and every passenger was just standing there staring at the black screen. Then I asked her, "What do all you people do？'
"We give the computer the information about your trip, and then it tells us whether you can fly with us or not."
"So when it goes down, you go down with it."
"That's good, sir. '
"How long will the computer be down？" I wanted to know.
"I have no idea. There's no way we can find out without asking the computer."
After the girl told me they had no backup (备用) computer, I said. "Let's forget the computer. What about your planes？ They're still flying, aren't they？"
"I wouldn't know," she said, pointing at the dark screen. "Only 'IT'knows. 'It'can't tell me.
By this time there were quite a few people standing in lines. The word soon spread to other travelers that the computer was down. Some people started to cry and still others kicked their luggage.
The best title for the article is______.
A．When the Computer Is Down
B．How to buy a ticket
C．The Computer of the Airport
D．Asking the Computer
