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听力对话原文
Conversation Two
M: How did you like yesterday’s astronomyclass?
W: It was interesting. But the point shewas trying to make seemed a little far-fetched.
M: Oh, that new theory that ocean watercame from comets?
W: Yeah. Do you remember what it was basedon?
M: Some recent satellite photos, I think.Apparently, space satellites recently detected thousands of small cometscolliding with earth’s outer atmosphere, almost 40,000 per day.
W: OK, they’re collided with atmosphere. Sothat’s what created the water?
M: It’s not the collision that createdwater. Comets contain water. They’re made up mostly of cosmic dust and water.When they collide with the atmosphere, they break up. And the water theycontain rains down to earth. Ocean water came from that rain.
W: Oh well, this morning I asked my geologyprofessor about that. He said that most geologists don’t accept it.
M: Why not?
W: Special research indicates that most ofthe water molecules from the comet would have burned up as they fell throughthe atmosphere. Enough rain couldn’t have reached the earth to fill up theocean.
M: Well, did the geologists have analternative theory to explain where ocean water came from?
W: Yeah, he said the more traditional viewis that the ocean water came from volcanoes.
M: From volcanoes?
W: Right. They say volcanic fumes aremostly steam. And they claimed that it was the volcanic steam that created theoceans, not rain from comets.
Questions 23 to 25 are based on theconversation you have just heard.
23. What are the speakers mainlydiscussing?
24. What did recent photographs from aspace satellite indicate?
25.What aspect of volcanoes does the woman mention?
