单选题
An unending flow of private and public criticism suggests that the people of the United States suffer【C1】______government, national, state and local, 【C2】______is corrupt and inefficient. The criticism reflects the【C3】______standards which the Americans have【C4】______as their ideals. The political system has provided the【C5】______for a society adapting itself【C6】______continuing rapid change【C7】______a scale never seen anywhere before, to immigration, to the development of the west, to the【C8】______of new technology, and to spontaneous economic【C9】______At the same time it has, 【C10】______the whole, avoided oppression and provided the means of expressing【C11】______well the wishes of this huge and【C12】______population, so that violent discontents have been【C13】______Finally, it has provided the 【C14】______for the United States to be a world【C15】______on a scale that has not been【C16】______before, using its power for influence , 【C17】______conquest【C18】______have been mistakes and tragedies, but【C19】______by the standard of human society as a whole they have been【C20】______, and overshadowed by successes.