L3
讲座
1. What is the main purpose of the lecture
To point out the flaws in a newly proposed theory
To describe a new understanding of a basic process in soil hydrology
To address concerns about using stable isotope analysis
To provide an explanation of a study described in the class’s textbook
2. What point does the professor emphasize about the region examined in the study he describes
Its steep mountainous position exaggerates the effects of water flow there.
Its dry climate limits how much information it can yield about water movement.
Its rainfall patterns and soil conditions are not typical of conditions in all regions.
Its soil absorbs water at a much greater rate than soil in a more temperate climate.
3. Why does the professor compare isotopes to fingerprints
To clarify a difficult concept
To identify a problem with the research study
To suggest a way to test a theory
To provide support for an argument
4. What did the researchers discover about small soil pores
Trees receive less water from small pores than from large pores.
Small pores retain water longer than previously thought.
Small pores make the movement of water through soil difficult to trace.
The number of small pores in the soil of a specific area is related to the number of hydrogen isotopes there.
5. In the soil examined by the researchers, what happens to rainwater that falls toward the end of the rainy season
Most of it moves through the soil to nearby streams.
Most of it is absorbed by trees.
It is more likely to pick up pollutants underground.
Researchers have been unable to track its entire path.
6. What is the professor’s opinion about the research findings
The findings are not conclusive because the movement of pollutants was not
tracked.
The findings provided valuable insights for a research study he conducted.
The findings support a different conclusion than the one the researchers have drawn.
The findings will have an impact on other fields of research.
