Do you know something about tree rings Do you know they can tell us what the weather was like, sometimes even hundreds of years ago
We can see the change of weather by studying the tree rings.
For example, to find out the weather of ten years ago, count (数) the rings of a tree from outside to the inside. If the tenth ring is far from the elh ring, then we are sure that it was sunny most of that year. If it is near to the elh ring, then the weather that year was bad.
Tree rings are important not only for studying the history (历史) of weather but also for studying the history of man. Many centuries ago there lived a lot of people at a place in New Mexico. But now you can find only sand there A scientist studied the rings of dead trees there. He found that the people had to leave because they had cut down all trees to make fires and buildings. As all trees had gone, the people there had to move.
Which two rings show the weather 12 years ago