听力音频：
L1
讲座
1. What is the lecture mainly about?
Structural differences between plants that live in wet and dry environments
The use of certain plants to help reduce flood damage to crops
Plants’ adaptations to a lack of oxygen in their environment
Ways that flooding interferes with a plant’s ability to photosynthesize
2. Why does the professor mention respiration?
To describe the relationship between photosynthesis and soil oxygen levels
To explain why flooded soil is a problem for most plants
To point out how some lilies get oxygen to their roots
To emphasize a difference between plants and animals
3. How have some plants adapted to avoid stress from flooding?
They have air spaces that extend from their roots to the leaves.
Their roots extend underground to touch the roots of other plants.
They drop older leaves to conserve energy.
They produce more leaves to increase photosynthesis.
4. What does the professor say about pneumatophores?（多选题）
They help plants photosynthesize.
They grow above ground.
They are found in some wetland plants.
They are a common adaptation in many crops.
5. What does the professor imply about stress tolerance in plants?
It is not yet well understood.
It is too complex to cover in the time she has left.
It is a less effective strategy for the plant than stress avoidance is.
It is difficult to distinguish from stress avoidance.
6. Why does the professor mention earthworm activity?
To point out earthworms’ role in the way plants absorb water
To point out a difference between common and uncommon soil types
To explain that earthworms can have a negative effect on a plant’s roots D. To
explain the reason for a characteristic of the soil she is describing
