We know that trees are useful in our everyday life. They   1    us many things, such as wood, oxygen(氧气), rubber, medicines and many other things. They can   2    tell us a lot about our climate. The following are the reasons. If you cut across a tree, you can   3    that it has many rings. Most trees grow one   4    ring every year. Because of this reason, we know   5   a tree is. A tree over a hundred years old means that it has more than a hundred    6   . When the climate is dry(干燥的) or very cold, the trees do not grow very much and their rings are usually   7   . When it is wet and   8   , the rings are much thicker. If the rings are suddenly very thin or suddenly very thick, this means that the    9    changed suddenly. If we look at the rings on the trees, we can   10    about the climate for a hundred years. We can see how our climate is changing today.

A．give B．ask C．get D．tell

A．too B．as well C．either D．also

A．hear B．feel C．see D．look

A．new B．old C．young D．short

A．how tall B．how old C．how long D．how far

A．leaves B．apples C．rings D．trees

A．big B．thin C．thick(厚的) D．long

A．cold B．cool C．hot D．warm

A．climate B．things C．people D．life

A．think B．talk C．learn D．change