A tree will grow well in a climate with lots of sunshine and rainfall(雨量). And little sunshine or rainfall will limit(限制)the growth of a tree. We can see the change of climate by studying the tree rings. For example, to find out the weather of ten years ago, count the rings of a tree from the outside to the inside. If the tenth ring is far from the eleventh ring, then we're sure that it was sunny and rainy most of that year. If it is near to the eleventh ring, then the climate that year was bad.