L2
讲座
1. What is the lecture mainly about?
How climate changes affect life on Earth
How Earth has been affected by living organisms
How physical and biological processes have cooled Earth’s atmosphere
How Earth’s climate determines its geology
2. What is the professor’s main point about cyanobacteria?
They caused a major change in Earth’s atmosphere.
They were probably the first life-form appear on early Earth.
They were responsible for rising global temperatures.
They had little effect on Earth’s geologic processes.
3. Why does the professor mention worms and fungi?
To emphasize the interdependence of plants and other organisms
To emphasize the importance of oxygen in the atmosphere
To point out factors that slowed the spread of plants on land
To give examples of organisms that helped form topsoil
4. What are two ways that land plants help cool the local climate?（多选题）
They help create strong air currents.
They produce large amounts of oxygen.
They take water from the ground and release it into the air.
They shade the areas beneath their leaf canopies.
5. What are two features of the geologic landscape that the professor attributes partly to biological processes?（多选题）
Temporary islands in rivers
Rounded hilltops
Curving rivers
Eroded riverbanks
6. What does the professor imply about rainforest destruction and pollution when he says this:
They require more research in order to be better understood.
They will not be the focus of the class lesson.
They are serious problems that are often ignored.
They are very similar to processes that happened billions of years ago.
