We know that trees are useful in our everyday life. They give us   1   things, such as wood, oxygen, rubber（橡胶）, medicines   2   many other things. They can also tell us a lot about our climate. The following are the reasons. If you cut   348   a tree, you can see that it has many rings. Most trees grow one new ring   4   year. Because of this, we know how old a tree is. A tree over a hundred   5   means that it has more than a hundred   6  . When the climate is dry or very cold, the trees do not grow very much and their rings   7   usually thin. When it is wet and warm, the rings

8  thicker. If the rings are suddenly very thin or suddenly very thick, it means that the 9  changed suddenly. If we look at the rings on the tree, we can learn about the climate in the past years. We can see

  10   changing today.

1.A．much               B．lot                  C．many        

2.A．so                 B．and                  C．while       

3.A．down               B．cross                    C．into        

4.A．every              B．many             C．some        

5.A．year old           B．old                  C．years old       

6.A．plants             B．rings                    C．leaves      

7.．A．is                   B．are                  C．were        

8.A．are much               B．are more             C．is much     

9.A．day                    B．year                 C．climate     

10.A．how our climate is    B．how is our climate   C．how to our climate

If someone is lost in a forest( 森林 ), he needs only study the trees around him carefully to find his way. On this half of the earth, he will find that the side of the tree with the most leaves and branches(树枝 ) is the south side. Also, by checking the tops of the trees, he will find that they lean(倾斜 ) to the south too.
Another sign( 标志物) for him to know where he is going is found in the bark.( 树皮) That is brighter on the south side.The remanining(树桩 ) of a cut tree is also a finder, for its rings can give him another sign. The rings will be thinner on the south side and thicker on the north side.
One more sign: some very small plants grow at the foot of a tree and they point to the north.
【小题1】 The passage is mainly about __________.
how to find a big tree if one is lost in the forest.
How to cut down trees in the forest
How to find the direction(方向 )in the forest
How to grow trees in the forest .
【小题2】 From a cut tree we can know that ___________.