Bolivia has a population of【56】. About one - tenth of the total population is white one - fourth are【57】Indians and white and more than half are【58】Indians. The government and【59】are【60】the control of white people. The Indians today live in【61】【62】their ancestors (祖先), most of whom were famers.【63】 work in the mines, for mining is the most important industry in Bolivia.【64】all the mining products,【65】is the most important, which【66】three fourths of all Bolivia's exports (出口). The eastern slopes (斜坡) of the Andes, since there are very few roads there, are fertile (富饶的)【67】not highly developed. The two primary【68】of transportation are river boats and porters. East of the hill region【69】the great plains【70】tropical (热带的) plants【71】. A【72】problem for Bolivia is the transport of food from the warm regions, where it is grown, to the mountainous regions, where most of the people live. Bolivia 【73】 its independence from Spain about a hundred years ago. It has been slow in developing,【74】its rich resources【75】a better future in it. (41)