Read the following passage and fill in the blanks with proper words （在下列短文内填入恰当的词，使其内容通顺，每空格限填一词，首字母已给）
Do you know something about rings （年轮）？Do you know they can tell us what the weather was like，sometimes even hundreds of years ago？
A tree will grow well in a climate with lots of sunshine and rainfall．And little sunshine or rainfall will limit the growth of a tree．We can see the c（69） of climate by studying the tree rings．For example，to find out the weather of ten years ago，we can count the rings of a tree from the o（70） to the inside．If the t（71） 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．
Tree rings are important not only for studying the history of weather but also for studying the history of m（72） ．Many centuries ago there l（73） a lot of people at a place in New Mexico．But now you can find only sand there-no trees and no people．What happened？
A scientist studied the rings of d（74） trees there．He found that the people had to leave because they had cut down all the trees to make fires and buildings．As all the trees had gone，the people there had to m．（75） ．