1.What is the main purpose of the lecture?
A. To help students understand what is required to launch a satellite
B. To describe new materials now being used to explore space
C. To describe a potential technology for space exploration
D. To show how ideas from science fiction often develop into actual technologies
2.Why does the student mention climbing a ladder?
A. To demonstrate his familiarity with certain new types of technology
B. To make sure he understands the point the professor is making
C. To raise an objection to the professor’s claims about escape velocity
D. To provide a humorous example for the other students’ amusement
3.What does the professor imply about using carbon nanotubes in the development of space elevators？
A. Current technology is good enough to make space elevators even without nanotubes.
B. We do not yet have the technology to bind nanotubes together in a ribbon.
C. Nanotube cables would not be rigid enough to support an elevator car.
D. Nanotubes are the kinds of materials that will be needed if space elevators are ever to be built.
4.According to the professor,what is the significance of having a satellite in orbit about 36,000 kilometers above Earth’s surface?
A. This is the physical limit of the length that a carbon nanotube cable could reach.
B. A satellite orbiting at this height can remain directly above on location on Earth.
C. Earth’s gravitational field is too weak to hold a satellite in orbit at higher altitudes.
D. The distance around Earth’s equator is approximately 36,000 kilometers.
5.Why does the professor mention the writer Arthur C. Clarke?
A. To use a comment made by Clarke as a way of answering a student’s question.
B. To familiarize students with Clarke’s ideas on space engineering.
C. To cite a prominent opponent of the idea of space elevators.
D. To point out that Clarke wrote about carbon nanotube technology long before it became a reality.
6.What can be inferred about the professor when he says this?
A. He is enjoying an opportunity to make his students laugh.
B. He is disappointed that none of his students thought of this idea themselves.
C. He wants his students to seriously consider an idea they might find surprising.
D. He has spent a great deal of time researching the idea that he is now presenting.