Most of the people who appear most often and most gloriously in the history books are great conquerors and generals and soldiers, whereas the people who really helped civilization forward are often never mentioned at all. We do not know who first set a broken leg, or launched a seaworthy boat, or calculated the length of the year, or manured a field; but we know all about the killers and destroyers. People think a great deal of them, so much so that on all the highest pillars in the great cities of the world you will find the figure of a conqueror or a general or a soldier. And I think most people believe that the greatest countries are those that have beaten in battle the greatest number of other countries and ruled over them as conquerors. It is just possible they are, but they are not the most civilized. Animals fight; so do savages; hence to be good at fighting is to be good in the way in which an animal or a savage is good, but it is not to be civilized. Even being good at getting other people to fight for you and telling them how to do it most efficiently—this, after all, is what conquerors and generals have done—is not being civilized. People fight to settle quarrels. Fighting means killing, and civilized peoples ought to be able to find some way of settling their disputes other than by seeing which side can kill off the greater number of the other side, and then saying that that side which has killed most has won. And not only has won, but, because it has won, has been in the right. For that is what going to war means; it means saying that might is right.
That is what the story of mankind has on the whole been like. Even our own age has fought the two greatest wars in history, in which millions of people were killed or mutilated. And while today it is true that people do not fight and kill each other in the streets—while, that is to say, we have got to the stage of keeping the rules and behaving properly to each other in daily life—nations and countries have not learnt to do this yet, and still behave like savages.
But we must not expect too much. After all, the race of men has only just started. From the point of view of evolution, human beings are very young children indeed, babies, in fact, of a few months old. Scientists reckon that there has been life of some sort on the earth in the form of jellyfish and that kind of creature for about twelve hundred million years; but there have been men for only one million years, and there have been civilized men for about eight thousand years at the outside. These figures are difficult to grasp; so let us scale them down. Suppose that we reckon the whole past of living creatures on the earth as one hundred years; then the whole past of man works out at about one month, and during that month there have been civilizations for between seven and eight hours. So you see there has been little time to learn in, but there will be oceans of time in which to learn better. Taking man’s civilized past at about seven or eight hours, we may estimate his future, that is to say, the whole period between now and when the sun grows too cold to maintain life any longer on the earth, at about one hundred thousand years. Thus mankind is only at the beginning of its civilized life, and as I say, we must not expect too much. The past of man has been on the whole a pretty beastly business, a business of fighting and bullying and gorging and grabbing and hurting. We must not expect even civilized peoples not to have done these things. All we can ask is that they will sometimes have done something else.
In the author’s opinion, the countries that ruled over a large number of other countries are（）
A. certainly not the greatest in any way
B. neither the greatest nor the most civilized
C. possibly the most civilized but not the greatest
D. possibly the greatest in some sense but not the most civilized
(Mg2+) = 0.15mol/L，c(Cl-) = 0.2mol/L，则c(NO3-)为（ ）