TOEFL Listening: ETS-TOEFL听力机经 - V9RA81RA95KN277SP$

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.