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英语沪教版八年级上册
Focusing on culture
of memory
The secret
Unit 7
Learning objectives
读懂关于“树的记忆”的文章，提取关键信息。
01
了解树木年轮的科学意义及其在历史、气候研究中的应用。
02
通过本课时的学习，学生能够：
重点
Do you think nature is able to remember past events If yes, how
Think and say
Human beings have the ability to remember the past.
Let’s explore.
1. What can you see
I can see tree trunks.
Look and say
2. What do you think these circles inside the tree trunk are
They are tree rings.
What do the tree rings show
Look and match
first year growth
rainy season
dry season
scar from forest fire
first year growth
rainy season
dry season
scar from forest fire
Read and answer
What is the main idea of the article
What are tree rings, and why are they called the “memories of trees”.
How do tree rings help us understand the past
How can scientists tell the age of a tree by looking at its tree rings
What do wide tree rings show
What do narrow tree rings mean
What does a black area on a tree ring mean
Read and answer
1. What is the main idea of the article
2. What are tree rings, and why are they called the “memories of trees”
3. How do tree rings help us understand the past
Tree rings can tell us things about the past.
Tree rings are the circles inside a tree trunk. Each year a tree grows, there is a new ring. The writer calls them the “memories of trees” because they contain information about the past. For example, they are a record of natural events and climate in the past.
Scientists can look at tree rings and learn about past climate change and natural disasters such as forest fires. They can also use tree rings to learn about human history. For example, scientists can study old wood and find out when the tree was cut down. They can also use it to to tell the age of old buildings.
Read and answer
4. How can scientists tell the age of a tree by looking at its tree rings
5. What do wide tree rings show
6. What do narrow tree rings mean
Scientists can tell the age of a tree by counting the rings inside the tree trunk.
A wide tree ring shows that the tree grew well that year. This happens when the tree gets enough sun and rain.
A narrow tree ring means that the tree did not grow as much that year. This can happen when a tree doesn’t get enough water.
7. What does a black area on a tree ring mean
A black area on a tree ring usually means there was a forest fire. Scientists can count the rings from the black area to determine when the fire happened.
Read and complete
Read the text carefully complete the mind map.
are a record of climate change
provide information about natural disasters
help us understand human history
Scientists study the ring patterns to learn about climate change in a place.
Scientists look at tree rings to study natural disasters.
Scientists use tree ring patterns to find the age of old buildings.
Read and answer
1. What is the name of the science that studies tree rings
This branch of science is called dendrochronology.
2. How do experts in this field collect data about the past using tree rings
They compare tree rings from different trees in the same area to collect data about the past.
Find the words and phrases in the article and match them with their meanings.
Find and match
Think and share
What else do you know about tree rings Share with your classmates.
Sometimes trees make extra rings or no rings in a year.
In the North, tree rings are wider on the south side—they can show you directions!
Some tree ring records are over 10,000 years old!
...
Discuss and say
What secrets can tree rings tell us
Age, climate, disasters, history.
What impressed you most today
Even though trees cannot speak, their rings contain secrets and act as a history book for our planet, telling stories about age, weather, disasters and human life long ago.
→ How Count the tree rings.
Summary
What can tree rings tell us
→ How Look at the width of tree rings.
Wide ring = Good year (sun + rain)
Narrow ring = Bad year (drought)
2. Climate / Environment
1. Age
What can tree rings tell us
→ How Look at the marks & chemistry.
Black scar = Forest fire
Chemistry = Date buildings / events (e.g., Viking village - 1021 CE)
Summary
3. History & Disasters
Homework
Share the interesting facts about tree rings with your friends.
01
To learn about how scientists study tree rings, you can try to explore the following questions:
How do they find trees to study
What tools do they use
What have they discovered about the past
Why is their work important
02
Bye-bye

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