[单项选择]

Passage Five
After Man has dreamed about flying for a long time. Michael Moshier is a dreamer. He invented the Solo Trek.
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
A. a solar powered engine
B. engine-powered twin fans
C. large flapping wings
D. rotating blades

Passage Five
After Man has dreamed about flying for a long time. Michael Moshier is a dreamer. He invented the Solo Trek.
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
A. how a helicopter flies
B. how the Jetsons fly
C. how the airphibian flies
D. how Superman flies

Man has been storing up useful knowledge about himself and the universe at the rate which has been spiraling upward for 10,000 years.

　　The (21) took a sharp upward leap with the invention of writing, but even (22) it remained painfully slow for several centuries. The next great leap forward (23) knowledge acquisition did not occur (24) the invention of movable type in the 15th century by Gutenberg and others. (25) to 1500, by the most optimistic (26) Europe was producing books at a rate of 1000 titles per year. This means that it (27) a full century to produce a library of 100,000 titles. By 1950, four and a half (28) later, the rate had accelerated so sharply that Europe was producing 120,000 titles a year. (29) once took a century now took only ten months. By 1960, a (30) decade later, the rate had made another significant jump, (31) a century’s work could be finished in seven
A. about
B. only
C. more than
D. less than