1. What is the main purpose of the lecture?
- A. To compare current theories about an astronomical phenomenon.
- B. To describe the growth of knowledge about an astronomical phenomenon.
- C. To illustrate how astronomical theories based on incorrect assumptions can lead to discoveries.
- D. To demonstrate that astronomers are able to predict events on the Sun based on cone.
2. According to the professor, what theories were proposed in the 1700s to account for the appearance of auroras?
[CHOOSE 2 ANSWERS]
- A. Auroras are caused by light refracting off ice and snow.
- B. Auroras are caused by CMES.
- C. Auroras occur when gases from sunspots hit glaciers.
- D. Auroras occur when an electric current between Earth’s poles is disrupted.
3. Why does the professor mention the duration of solar eclipses?
- A. To demonstrate the importance of the coronagraph as a research tool.
- B. To describe the effects of solar eclipses on auroras.
- C. To support a conclusion about the connection between sunspot cycles and other solar phenomenon.
- D. To explain why auroras are infrequent.
4. How do sunspots contribute to auroras?
- A. Sunspots increase the intensity of Earth’s magnetic field at the poles.
- B. Sunspots emit charged particles that collide with atoms in Earth’s upper atmosphere.
- C. Sunspots bombard Earth with oxygen and nitrogen atoms.
- D. Sunspots cause temperature changes at Earth’s poles.
5. What point does the professor make when he talks about disruptions to technology?
- A. Disruptions are more prevalent in the northern hemisphere than in the southern hemisphere.
- B. Observing aurora activity has proven to be a better way to predict CMES than using other devices.
- C. CMES and other magnetic activity on the Sun can have far-reaching effect.
- D. Most information about aurora intensity has been obtained through observation with the naked eye.
6. Why does the professor say this：
- A. He hopes that one of the students will explain the answer to the others.
- B. He believes that the answer should be obvious to the students.
- C. He thinks the point is not relevant to today’s lecture.
- D. He does not remember if he covered the point in another lecture.