【正确答案】 B

【答案解析】[听力原文]
   Life on earth depends on the sun. Day after day we see its light and feel its warmth, but we do not often consider their origin. Yet there are many remarkable things about the sun. One is its distance from the earth. This is about 93 million miles. A journey of this distance, even if it could be made, would take several hundred years even in the fastest rocket.
   The sun makes us feel hot, even at a distance of 93 million miles. This is not surprising. The temperature on the sun is about 10,000 degrees Fahrenheit. But we receive only a small part of the heat. The total heat of the sun could melt a column of ice two and a quarter miles thick and 93 million miles high in a second.
   The brightness of the sun is equally astonishing. As we said earlier, we receive only a very small part of the sun's heat. We also receive only a very small part of its light. This is sufficient for the growth of trees and plants, and for the existence of living creatures on earth. Too much heat and light would destroy the balance of life. The heat and light from the sun come in just the right quantifies for life on earth.
   What remarkable things are mentioned in the passage?