77. How Fast Can a Future Airplane Travel?

According to the essay, what is the main advantage of supersonic airplanes compared to current passenger planes?
1. They are much safer and more affordable.
2. They can carry many more passengers.
3. They can cut travel time in half.
4. They have a much smaller environmental effect.
Based on the text, what does "supersonic" mean?
1. Faster than the speed of light.
2. Slower than the speed of sound.
3. Five times the speed of sound.
4. Faster than the speed of sound.
The essay states that a hypersonic airplane could travel at what speed?
1. About 900 kilometers per hour.
2. About 1,235 kilometers per hour.
3. Over 6,000 kilometers per hour.
4. About 560 miles per hour.
What are two main challenges mentioned for building very fast future airplanes?
1. Finding enough pilots and building larger airports.
2. Surviving heat from air friction and creating more powerful engines.
3. Making them quieter and adding more passenger comforts.
4. Navigating bad weather and avoiding other aircraft.
How does the essay suggest faster airplanes could change the world?
1. By making international travel more expensive.
2. By making the world feel smaller and helping people connect more quickly.
3. By replacing all other forms of transportation like cars and trains.
4. By allowing people to live in airplanes instead of houses.