学进去

Choose the best words or expressions and complete the passage (选择最恰当的单词或词语完成短文)
We know that trees are useful in our_______________life. They give us wood,oxygen, rubber, medicine and many other things. They can_______________tell us about our climate (气候). If you_______________a tree trunk, you can see that it has many rings (年轮).Most trees grow one new ring every year. Because of this reason, we know the_______________of a tree. A tree over a hundred years old means that it has more than a hundred rings. When the climate is dry or very cold, the trees do not grow very much and their rings are usually_______________. When it is wet and warm, the rings are much thicker. If the rings are suddenly very thin or suddenly very thick, this means that the climate changed suddenly. We can learn about the climate for a hundred years. We can see_______________our climate is changing today.

1．	A．every day B．everyday C．every day's D．every day's

2．	A．not B．too C．to D．also

3．	A．cut across B．climb up C．walk past D．look at

4．	A．size B．length C．age D．weight

5．	A．big B．thick C．small D．thin

6．	A．how B．why C．when D．what