2019-2020学年度第 44 期总第 797 期
Avoiding extinction (P4-5)
江苏省南菁高级中学 杨琰

Lead-in
Extinct animals
 
Dinosaurs

Activity 1
What caused the extinction of dinosaurs? Volcanic eruptions? Extreme climate? Asteroid impacts?

Activity 2
Read the passage quickly and find out cause of the Late Devonian extinction according to the article.
A broken ozone layer

Activity 3: process of the research
 

Activity 4: findings of the research
Read Paragraphs 3-4 and find the relevant information.
Finding 1:
These spores were vulnerable to ultra-violet (UV) radiation.
The evidence: These spores were found misshapen, suggesting that their DNA had been damaged by UV radiation.

Finding 2:
Many of the spores had their walls darkened.

What does this result indicate?
1. The UV levels were unusually high.
2. All of the ozone protection was gone.

Activity 5
Think further.
1. What does the writer mean by “sound familiar“?
2. What would the earth be like if the ozone layer was destroyed?
3. How should we protect the ozone layer?

1. What does the writer mean by “sound familiar“?
The current situation is similar to the Late Devonian extinction, as if the history is repeating itself.
According to the study, a similar collapse of the ozone layer could occur again.

2.What would the earth be like if the ozone layer was destroyed?
All of the ozone protection would be gone. The melting ice sheets would quickly release a large amount of heat into the air, pushing more naturally generated ozone-destroying chemicals into the atmosphere. This would move us from the current state of climate change to a climate emergency.

3. How should we protect the ozone layer?
Reduce the emission of carbon dioxide;
Reduce the usage of FREON（氟利昂）and find an environmentally-friendly substitute.

Language focus
Find the following expressions in the passage.

大范围火山喷发
large-scale volcanic eruptions
收集古代的石头样本
collect ancient rock samples
易受到紫外线的伤害
be vulnerable to ultra-violet radiation
被裸露在太多的阳光下
be exposed to too much sunlight
释放大量的热量到空气中
release a large amount of heat into the air
考虑到现有的全球变暖现状
given the current state of global warming
同样的臭氧层崩溃
a similar collapse of the ozone layer
认真地对待臭氧层的保护
take the protection of the ozone layer seriously

Assignment
Summarize the whole passage in 60 words.