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Listen to an Academic Talk Test #038
Listen to an Academic Talk
1. What is the main topic of the talk?
A) The differences between hot springs and geysers
B) The chemical composition of geyser water
C) The conditions required for geysers to form
D) The dangers associated with volcanic areas
2. According to the professor, what keeps the superheated water from boiling initially?
A) The lack of an underground heat source
B) The presence of constrictions in the rock
C) The cool temperature of the groundwater
D) The pressure from the water above it
3. What does the professor imply about the locations of geysers?
A) They are found in many places around the world.
B) They are becoming more common due to climate change.
C) They are found only in geographically specific areas.
D) They are difficult to locate and study.
4. Why does the professor mention a "plumbing system"?
A) To compare a geyser to a household appliance
B) To describe the man-made structures around geysers
C) To explain the network of underground channels
D) To illustrate how water is supplied to the area
Professor: Let's discuss a remarkable geological feature: the geyser. A geyser is essentially a hot spring that periodically erupts, shooting a tower of hot water and steam into the air. For a geyser to exist, you need a very specific set of conditions. First, you need an intense source of heat close to the surface, typically magma. Second, you need a plentiful source of groundwater. And third, you need a special kind of underground plumbing system with constrictions. What happens is, water seeps into this system and gets superheated by the magma, well above its normal boiling point. But the pressure from the water above keeps it in a liquid state. Eventually, some water near the top boils, pushing out the water above it. This releases the pressure on the superheated water below, which then flashes instantly into steam, violently ejecting the entire column of water. This is why geysers are so rare; these three conditions are seldom met in the same place.
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