Being a man has always been dangerous.There are about 105 males born for every 100 females，but this ratio drops to near balance at the age of maturity，and among 70_year_olds there are twice as many women as men.But the great universal of male mortality is being changed.Now，boy babies survive almost as well as girls do.This means that，for the first time，there will be an excess of boys in those crucial years when they are searching for a mate.More important，another chance for natural selection has been removed.Fifty years ago，the chance of a baby （particularly a boy baby） surviving depended on its weight.A kilogram too light or too heavy meant death almost certain.Today it makes almost no difference.Since much of the variation is due to genes，one more agent of evolution has gone.
There is another way to commit evolutionary suicide：stay alive，but have fewer children.Few people are as fertile as in the past.Except in some religious communities，very few women have 15 children.Nowadays the number of births，like the age of death，has become average.Most of us have roughly the same number of offspring.Again，differences between people and the opportunity for natural selection to take advantage of it have diminished.India shows what is happening.The country offers wealth for a few in the great cities and poverty for the remaining tribal peoples.The grand mediocrity of today-everyone being the same in survival and number of offspring-means that natural selection has lost 80% of its power in upper_middle_class India compared to the tribes.
For us，this means that evolution is over； the biological Utopia has arrived.Strangely，it has involved little physical change.No other species fills so many places in nature.But in the past 100，000 years-even the past 100 years-our lives have been transformed but our bodies have not.We did not evolve，because machines and society did it for us.Darwin had a phrase to describe those ignorant of evolution：they“look at an organic being as a savage looks at a ship，as at something wholly beyond his comprehension.”No doubt we will remember a 20th century way of life beyond comprehension for its ugliness.But however amazed our descendants may be at how far from Utopia we were，they will look just like us.
Which of the following would be the best title for the passage？
［A］Sex Ratio Changes in Human Evolution
［B］Ways of Continuing Man's Evolution
［C］The Evolutionary Future of Nature
［D］Human Evolution Going Nowhere［2000.58］
Scattered around the globe are more than 100 small regions of isolated volcanic activity known to geologists as hot spots. Unlike most of the world's volcanoes， they are not always found at the boundaries of the great drifting plates that make up the earth's surface； on the contrary， many of them lie deep in the interior of a plate. Most of the hot spots move only slowly， and in some cases the movement of the plates past them has left trails of dead volcanoes. The hot spots and their trails are milestones that mark the passage of the plates.
That the plates are moving is not beyond dispute. Africa and South America， for example， are moving away from each other as new material is injectedsintosthe sea floor between them. The complementary coastlines and certain geological features that seem to span the ocean are reminders ofswheresthe two continents were once joined. The relative motion of the plates carrying these continents has been constructed in detail， but the motion of one plate with respect to another cannot readily be translatedsintosmotion with respect to the earth's interior. It is not possible to determine whether both continents are moving in opposite directions or whether one continent is stationary and the other is drifting away from it. Hot spots， anchored in the deeper layers of the earth， provide the measuring instruments needed to resolve the question. From an analysis of the hot_spot population it appears that the African plate is stationary and that it has not moved during the past 30 million years.
The significance of hot spots is not confined to their role as a frame of reference. It now appears that they also have an important influence on the geophysical processes that propel the plates across the globe. When a continental plate come to rest over a hot spot， the material rising from deeper layer creates a broad dome. As the dome grows， it develops seed fissures （cracks）； in at least a few cases the continent may break entirely along some of these fissures， so that the hot spot initiates the formation of a new ocean. Thus just as earlier theories have explained the mobility of the continents， so hot spots may explain their mutability （inconstancy）。
The passage is mainly about.
［A］the features of volcanic activities
［B］the significance of hot spots in geophysical studies
［C］the importance of the theory about drifting plates
［D］the process of the formation of volcanoes［1998.70］
When a new movement in art attains a certain fashion，it is advisable to find out what its advocates are aiming at，for，however farfetched and unreasonable their principles may seem today，it is possible that in years to come they may be regarded as normal.With regard to Futurist poetry，however，the case is rather difficult，for whatever Futurist poetry may be-even admitting that the theory on which it is based may be right-it can hardly be classed as Literature.
This，in brief，is what the Futurist says：for a century，past conditions of life have been conditionally speeding up，till now we live in a world of noise and violence and speed.Consequently，our feelings，thoughts and emotions have undergone a corresponding change.This speeding up of life， says the Futurist，requires a new form of expression.We must speed up our literature too，if we want to interpret modern stress.We must pour out a large stream of essential words，unhampered by stops，or qualifying adjectives，or finite verbs.Instead of describing sounds we must make up words that imitate them；we must use many sizes of type and different colored inks on the same page，and shorten or lengthen words at will.
Certainly their descriptions of battles are confused. But it is a little upsetting to read in the explanatory notes that a certain line describes a fight between a Turkish and a Bulgarian officer on a bridge off which they both fallsintosthe river-and then to find that the line consists of the noise of their falling and the weights of the officers：“Pluff！ Pluff！ A hundred and eighty_five kilograms.”
This，though it fulfills the laws and requirements of Futurist poetry，can hardly be classed as Literature.All the same，no thinking man can refuse to accept their first proposition：that a great change in our emotional life calls for a change of expression. The whole question is really this：have we essentially changed？
This passage is mainly.
［A］a survey of new approaches to art
［B］a review of Futurist poetry
［C］about merits of the Futurist movement
［D］about laws and requirements of literature［2000.59］