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.
小题1:A．much B．lot C．many
小题2:A．so B．and C．while
小题3:A．down B．cross C．into
小题4:A．every B．many C．some
小题5:A．year old B．old C．years old
小题6:A．plants B．rings C．leaves
小题7:．A．is B．are C．were
小题8:A．are much B．are more C．is much
小题9:A．day B．year C．climate
小题10:A．how our climate is B．how is our climate C．how to our climate